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Which is the right note?
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Long Call Option Trading Strategy: Learn the Basics LONG CALL SUMMARY Purchasing a call option is a bullish strategy that gives the buyer the right, but not the obligation, to buy 100 shares of the underlying asset at a specified strike price on or before the expiration date. This strategy is typically employed when an investor believes that the price of the underlying asset will increase in the future. The value of a call option is influenced by several factors, including the underlying asset's price, the strike price, the time to expiration, and implied volatility. As the price of the underlying asset increases and approaches or breaches the long call's strike price, the option's value will appreciate. This is because the option holder has the right to buy the underlying asset at a lower price than the current market price, resulting in a potential profit. Out-of-the-money (OTM) calls have a strike price that is higher than the current market price of the underlying asset. These options are typically cheaper than in-the-money (ITM) calls, which have a strike price lower than the current market price. ITM calls have intrinsic value, which is the difference between the strike price and the current market price, and extrinsic value, which is the additional premium paid for the option's time value. Extrinsic value decays over time as the option approaches expiration, and this can cause the option to lose value, especially if the underlying asset does not move towards the strike price. LONG CALL OPTION Purchasing a call option grants you the privilege, but not the responsibility, to buy 100 shares of the underlying asset at the specified strike price on or before the expiration date. This option grants you the flexibility to capitalize on potential price increases of the underlying asset. The value of a call option is positively correlated with the price of the underlying asset. As the price of the stock or ETF rises and approaches your strike price, the value of your call option increases. This is because the difference between the market price and the strike price widens, giving you a greater potential profit. This characteristic makes call options suitable for bullish strategies where investors anticipate price increases. Conversely, the value of a call option diminishes when the price of the underlying asset drops or remains constant. Time decay, which refers to the gradual loss of an option's value as its expiration date approaches, also contributes to the depreciation of call options. Over time, the intrinsic value of the option, which represents the difference between the strike price and the underlying asset's market price, decreases as the option nears expiration. Additionally, if the price of the underlying asset remains below the strike price, the option may expire worthless, resulting in a total loss of the premium paid. Understanding these dynamics is crucial when trading call options. It allows you to make informed decisions about when to enter and exit positions, taking into account factors such as the underlying asset's price movements, time decay, and market sentiment. Buying call options can provide an alternative strategy to gain long exposure to a stock's price movement without the need for purchasing shares directly. This approach, known as a long call position, offers the potential advantage of lower capital outlay compared to buying shares outright. However, it's crucial to understand the concept of time decay, which significantly impacts the value of long call options. Time decay refers to the gradual decrease in the value of an option as time passes. This phenomenon occurs due to two primary factors: theta and vega. Theta measures the rate at which an option's value decays over time, while vega measures the sensitivity of an option's price to changes in implied volatility. As the expiration date of the call option approaches, both theta and vega work together to erode the option's value. Consequently, to offset the impact of time decay, the underlying stock price must rise at a greater velocity towards the call option's strike price. This is because the intrinsic value of a call option, which represents the difference between the strike price and the underlying stock's current market price, increases as the stock price moves higher. Another important consideration when evaluating call options is the distinction between out-of-the-money (OTM) and in-the-money (ITM) calls. OTM calls have a strike price higher than the current market price of the underlying stock, while ITM calls have a strike price lower than the current market price. OTM calls are typically less expensive than ITM calls because their value is composed entirely of extrinsic value. Extrinsic value refers to the portion of an option's price that is not attributable to its intrinsic value. ITM calls, on the other hand, have both intrinsic and extrinsic value, resulting in a higher cost per contract. As time relentlessly marches forward, the value of call options undergoes a transformation. The extrinsic value, which represents the premium paid for the potential of future price movements, steadily diminishes as expiration approaches. This decay is universal, affecting all call options regardless of their initial strike price or distance from the underlying asset's current price. However, amidst this gradual erosion of extrinsic value, ITM (in-the-money) call options stand as an exception. These options retain their intrinsic value at expiration, which is the difference between the strike price and the underlying asset's price. This characteristic sets ITM call options apart from their OTM (out-of-the-money) counterparts, whose extrinsic value decays entirely to zero near or at expiration. The distinction between ITM and OTM call options underscores the significance of carefully considering both the time frame and strike price when making investment decisions. Traders seeking to maximize their potential gains through call options must be mindful of the impending decay of extrinsic value as expiration draws near. For long ITM call options, the ideal scenario is for the underlying asset to exhibit a significant upward movement. Such a price increase would enhance the intrinsic value of the option, making it worth more at expiration than the initial purchase price. This scenario holds true for OTM call options as well, as they require the underlying asset to move ITM at expiration to possess any value. Prior to expiration, both OTM and ITM call options have the potential to gain a combination of extrinsic and intrinsic value if the stock exhibits a rapid upward trajectory. This dynamic underscores the importance of monitoring market conditions and adjusting investment strategies accordingly. Understanding the Interplay of Time, Strike Price, and Option Value in Call Option Trading: In the realm of call option trading, comprehending the intricate interplay between time, strike price, and option value is paramount to success. These three factors collectively shape the dynamics of call option contracts, allowing traders to make informed decisions and capitalize on market opportunities. Time (Days to Expiration): Time, measured in days until expiration, is a crucial element in call option trading. As expiration approaches, the value of a call option is directly influenced by the time premium. The closer an option gets to expiration, the less time value it holds. This time decay accelerates in the final days leading up to expiration. Therefore, traders must carefully consider the time factor when selecting their expiration dates. Strike Price: The strike price represents the predetermined price at which the underlying asset can be bought (in the case of a call option) or sold (in the case of a put option). When choosing a strike price, traders must assess the current market price of the underlying asset and make an educated guess about its future direction. ITM (In-the-Money) call options are those with a strike price below the current market price, while OTM (Out-of-the-Money) call options have a strike price above the current market price. Option Value: Option value refers to the premium paid by the buyer of an option contract to the seller. This premium comprises two components: intrinsic value and time value. Intrinsic value is the difference between the strike price and the underlying asset's current market price. Time value, as mentioned earlier, is the premium paid for the remaining time until expiration. Auto-Exercise and Expiration Scenarios: Auto-Exercise: Long call options that expire ITM by $0.01 or more will be automatically exercised. This means that the buyer of the call option has the right to purchase the underlying asset at the strike price. If the investor holds only a long call, this will result in 100 long shares per contract purchased at the call option's strike price. On the other hand, investors holding the corresponding short shares will cover or buy shares at the call option's strike price. Expiration Worthless: Any long call options that expire OTM will expire worthless. In this scenario, the investor loses the entire premium paid for the contract, resulting in a maximum loss. Understanding these concepts is instrumental in developing effective call option trading strategies. By carefully considering the interplay between time, strike price, and option value, traders can position themselves to make profitable trades and minimize potential losses. PROFIT & LOSS DIAGRAM OF A LONG OTM CALL A long OTM call option can be profitable if the current market value of the option exceeds the price paid to purchase it. This can occur in two main scenarios: Stock Price Surpasses Strike Price: If the underlying asset's price rises above the strike price of the call option by more than the premium paid for the option, the call option becomes profitable. This is because the intrinsic value of the call option (the difference between the strike price and the underlying asset's price) becomes positive, and the call option can be exercised to purchase the underlying asset at a price below the market price. OTM Call Moves Closer to Underlying Asset Price: Even if the underlying asset's price does not reach the strike price, a long OTM call can still be profitable if the option's price increases. This can happen when there is a quick rally in the underlying asset's price, causing the call option's price to increase as well, even if the strike price is not reached. This is because the time value of the call option increases as the expiration date approaches, and the call option becomes more likely to be in the money. However, it's important to note that long OTM call options can also result in losses if the underlying asset's price does not surpass the breakeven point. The breakeven point is the price at which the call option's intrinsic value becomes equal to the purchase price of the option. If the underlying asset's price remains below the breakeven point until expiration, the call option will expire worthless, and the investor will lose the entire amount paid for the option. The maximum profit potential of a long OTM call option indeed has no theoretical limit, as a stock's price can theoretically rise indefinitely. This means that if the underlying stock price increases significantly, the call option holder can potentially reap substantial profits by exercising the option and buying the stock at the predetermined strike price. On the downside, the maximum loss on a long call option is limited to the premium paid for the option. This premium represents the total amount invested in the option contract and acts as a protective barrier against further losses. If the stock price declines or stays below the strike price at expiration, the option will expire worthless, and the investor will lose the entire premium paid. The flattened red loss zone in the diagram illustrates this limited loss potential. This zone represents the range of stock prices below the strike price at expiration where the option holder will lose money. The loss amount decreases as the stock price approaches the strike price and becomes zero when the stock price equals the strike price. Beyond the strike price, the option holder starts to make a profit. It's important to note that while the maximum profit potential is theoretically unlimited, it is highly unlikely for a stock price to rise dramatically within the short timeframe of an OTM option's expiration period. Therefore, while the potential rewards can be significant, the probability of achieving them is relatively low. PROFIT & LOSS DIAGRAM OF A LONG ITM CALL ITM (In-the-Money) options have a unique characteristic where the price of their intrinsic value directly correlates with the underlying asset's price. This means that for every one point movement in the underlying asset's price, the ITM option's intrinsic value moves by the same amount. While purchasing an ITM option provides immediate intrinsic value, it does not guarantee profitability upon execution. Similar to buying an OTM (Out-of-the-Money) call option, the purchase price of an ITM call must increase for it to be profitable. This requires the stock price to move further above the call strike price. This relationship is visually represented in the diagram, where the red and green zones converge on the x-axis. The maximum potential loss on a long call option is limited to the debit paid for the option, which is represented by the flattened red area in the diagram. This means that the most an investor can lose on a long call is the premium paid for the option, regardless of how far the underlying asset's price moves below the strike price. Understanding the price dynamics and potential risks associated with ITM options is crucial for traders and investors. While ITM options offer immediate intrinsic value, careful analysis and consideration of market conditions are necessary to determine their potential profitability. EXAMPLE OF A LONG OTM CALL OPTION XYZ currently trading @ $45 Buy to Open +1 XYZ 50-strike call @ $4 debit Cost: $4 debit ($400 total, ($4 x 100 shares)) Time Decay Affect Works against the optionâs value Max Profit Theoretically unlimited Max Loss Debit paid per contract ($400) Breakeven Price (at expiration) Strike price + debit paid ($54) Account Type Required Cash, Margin, and IRA EXAMPLE OF A LONG ITM CALL OPTION XYZ currently trading @ $45 Buy to Open +1 XYZ 40-strike call @ $7 debit ($5 intrinsic value + $2 extrinsic value) Cost: $7 debit ($700 total) Time Decay Affect Works against the optionâs value Max Profit Theoretically unlimited Max Loss Debit paid per contract ($700) Breakeven Price (at expiration) Strike price + debit paid ($47) Account Type Required Cash, Margin, and IRA
âThereâs No Such Thing as Sound Scienceâ by By Christie Aschwanden was a lead science writer for FiveThirtyEight. FiveThirtyEight, Science, Dec. 6, 2017 Science is being turned against itself. For decades, its twin ideals of transparency and rigor have been weaponized by those who disagree with results produced by the scientific method. Under the Trump administration, that fight has ramped up again. In a move ostensibly meant to reduce conflicts of interest, Environmental Protection Agency Administrator Scott Pruitt has removed a number of scientists from advisory panels and replaced some of them with representatives from industries that the agency regulates. Like many in the Trump administration, Pruitt has also cast doubt on the reliability of climate science. For instance, in an interview with CNBC, Pruitt said that âmeasuring with precision human activity on the climate is something very challenging to do.â Similarly, Trumpâs pick to head NASA, an agency that oversees a large portion the nationâs climate research, has insisted that research into human influence on climate lacks certainty, and he falsely claimed that âglobal temperatures stopped rising 10 years ago.â Kathleen Hartnett White, Trumpâs nominee to head the White House Council on Environmental Quality, said in a Senate hearing last month that she thinks we âneed to have more precise explanations of the human role and the natural roleâ in climate change. The same entreaties crop up again and again: We need to root out conflicts. We need more precise evidence. What makes these arguments so powerful is that they sound quite similar to the points raised by proponents of a very different call for change thatâs coming from within science. This other movement strives to produce more robust, reproducible findings. Despite having dissimilar goals, the two forces espouse principles that look surprisingly alike: Science needs to be transparent. Results and methods should be openly shared so that outside researchers can independently reproduce and validate them. The methods used to collect and analyze data should be rigorous and clear, and conclusions must be supported by evidence. These are the arguments underlying an âopen scienceâ reform movement that was created, in part, as a response to a âreproducibility crisisâ that has struck some fields of science.1 But theyâre also used as talking points by politicians who are working to make it more difficult for the EPA and other federal agencies to use science in their regulatory decision-making, under the guise of basing policy on âsound science.â Scienceâs virtues are being wielded against it. What distinguishes the two calls for transparency is intent: Whereas the âopen scienceâ movement aims to make science more reliable, reproducible and robust, proponents of âsound scienceâ have historically worked to amplify uncertainty, create doubt and undermine scientific discoveries that threaten their interests. âOur criticisms are founded in a confidence in science,â said Steven Goodman, co-director of the Meta-Research Innovation Center at Stanford and a proponent of open science. âThatâs a fundamental difference â weâre critiquing science to make it better. Others are critiquing it to devalue the approach itself.â Calls to base public policy on âsound scienceâ seem unassailable if you donât know the termâs history. The phrase was adopted by the tobacco industry in the 1990s to counteract mounting evidence linking secondhand smoke to cancer. A 1992 Environmental Protection Agency report identified secondhand smoke as a human carcinogen, and Philip Morris responded by launching an initiative to promote what it called âsound science.â In an internal memo, Philip Morris vice president of corporate affairs Ellen Merlo wrote that the program was designed to âdiscredit the EPA report,â âprevent states and cities, as well as businesses from passing smoking bansâ and âproactivelyâ pass legislation to help their cause. The sound science tactic exploits a fundamental feature of the scientific process: Science does not produce absolute certainty. Contrary to how itâs sometimes represented to the public, science is not a magic wand that turns everything it touches to truth. Instead, itâs a process of uncertainty reduction, much like a game of 20 Questions. Any given study can rarely answer more than one question at a time, and each study usually raises a bunch of new questions in the process of answering old ones. âScience is a process rather than an answer,â said psychologist Alison Ledgerwood of the University of California, Davis. Every answer is provisional and subject to change in the face of new evidence. Itâs not entirely correct to say that âthis study proves this fact,â Ledgerwood said. âWe should be talking instead about how science increases or decreases our confidence in something.â The tobacco industryâs brilliant tactic was to turn this baked-in uncertainty against the scientific enterprise itself. While insisting that they merely wanted to ensure that public policy was based on sound science, tobacco companies defined the term in a way that ensured that no science could ever be sound enough. The only sound science was certain science, which is an impossible standard to achieve. âDoubt is our product,â wrote one employee of the Brown & Williamson tobacco company in a 1969 internal memo. The note went on to say that doubt âis the best means of competing with the âbody of factââ and âestablishing a controversy.â These strategies for undermining inconvenient science were so effective that theyâve served as a sort of playbook for industry interests ever since, said Stanford University science historian Robert Proctor. The sound science push is no longer just Philip Morris sowing doubt about the links between cigarettes and cancer. Itâs also a 1998 action plan by the American Petroleum Institute, Chevron and Exxon Mobil to âinstall uncertaintyâ about the link between greenhouse gas emissions and climate change. Itâs industry-funded groupsâ late-1990s effort to question the science the EPA was using to set fine-particle-pollution air-quality standards that the industry didnât want. And then there was the more recent effort by Dow Chemical to insist on more scientific certainty before banning a pesticide that the EPAâs scientists had deemed risky to children. Now comes a move by the Trump administrationâs EPA to repeal a 2015 rule on wetlands protection by disregarding particular studies. (To name just a few examples.) Doubt merchants arenât pushing for knowledge, theyâre practicing what Proctor has dubbed âagnogenesisâ â the intentional manufacture of ignorance. This ignorance isnât simply the absence of knowing something; itâs a lack of comprehension deliberately created by agents who donât want you to know, Proctor said.2 In the hands of doubt-makers, transparency becomes a rhetorical move. âItâs really difficult as a scientist or policy maker to make a stand against transparency and openness, because well, who would be against it?â said Karen Levy, researcher on information science at Cornell University. But at the same time, âyou can couch everything in the language of transparency and it becomes a powerful weapon.â For instance, when the EPA was preparing to set new limits on particulate pollution in the 1990s, industry groups pushed back against the research and demanded access to primary data (including records that researchers had promised participants would remain confidential) and a reanalysis of the evidence. Their calls succeeded and a new analysis was performed. The reanalysis essentially confirmed the original conclusions, but the process of conducting it delayed the implementation of regulations and cost researchers time and money. Delay is a time-tested strategy. âGridlock is the greatest friend a global warming skeptic has,â said Marc Morano, a prominent critic of global warming research and the executive director of ClimateDepot.com, in the documentary âMerchants of Doubtâ (based on the book by the same name). Moranoâs site is a project of the Committee for a Constructive Tomorrow, which has received funding from the oil and gas industry. âWeâre the negative force. Weâre just trying to stop stuff.â Some of these ploys are getting a fresh boost from Congress. The Data Quality Act (also known as the Information Quality Act) was reportedly written by an industry lobbyist and quietly passed as part of an appropriations bill in 2000. The rule mandates that federal agencies ensure the âquality, objectivity, utility, and integrity of informationâ that they disseminate, though it does little to define what these terms mean. The law also provides a mechanism for citizens and groups to challenge information that they deem inaccurate, including science that they disagree with. âIt was passed in this very quiet way with no explicit debate about it â that should tell you a lot about the real goals,â Levy said. But whatâs most telling about the Data Quality Act is how itâs been used, Levy said. A 2004 Washington Post analysis found that in the 20 months following its implementation, the act was repeatedly used by industry groups to push back against proposed regulations and bog down the decision-making process. Instead of deploying transparency as a fundamental principle that applies to all science, these interests have used transparency as a weapon to attack very particular findings that they would like to eradicate. Now Congress is considering another way to legislate how science is used. The Honest Act, a bill sponsored by Rep. Lamar Smith of Texas,3 is another example of what Levy calls a âTrojan horseâ law that uses the language of transparency as a cover to achieve other political goals. Smithâs legislation would severely limit the kind of evidence the EPA could use for decision-making. Only studies whose raw data and computer codes were publicly available would be allowed for consideration. That might sound perfectly reasonable, and in many cases it is, Goodman said. But sometimes there are good reasons why researchers canât conform to these rules, like when the data contains confidential or sensitive medical information.4 Critics, which include more than a dozen scientific organizations, argue that, in practice, the rules would prevent many studies from being considered in EPA reviews.5 It might seem like an easy task to sort good science from bad, but in reality itâs not so simple. âThereâs a misplaced idea that we can definitively distinguish the good from the not-good science, but itâs all a matter of degree,â said Brian Nosek, executive director of the Center for Open Science. âThere is no perfect study.â Requiring regulators to wait until they have (nonexistent) perfect evidence is essentially âa way of saying, âWe donât want to use evidence for our decision-making,ââ Nosek said. Most scientific controversies arenât about science at all, and once the sides are drawn, more data is unlikely to bring opponents into agreement. Michael Carolan, who researches the sociology of technology and scientific knowledge at Colorado State University, wrote in a 2008 paper about why objective knowledge is not enough to resolve environmental controversies. âWhile these controversies may appear on the surface to rest on disputed questions of fact, beneath often reside differing positions of value; values that can give shape to differing understandings of what âthe factsâ are.â Whatâs needed in these cases isnât more or better science, but mechanisms to bring those hidden values to the forefront of the discussion so that they can be debated transparently. âAs long as we continue down this unabashedly naive road about what science is, and what it is capable of doing, we will continue to fail to reach any sort of meaningful consensus on these matters,â Carolan writes. The dispute over tobacco was never about the science of cigarettesâ link to cancer. It was about whether companies have the right to sell dangerous products and, if so, what obligations they have to the consumers who purchased them. Similarly, the debate over climate change isnât about whether our planet is heating, but about how much responsibility each country and person bears for stopping it. While researching her book âMerchants of Doubt,â science historian Naomi Oreskes found that some of the same people who were defending the tobacco industry as scientific experts were also receiving industry money to deny the role of human activity in global warming. What these issues had in common, she realized, was that they all involved the need for government action. âNone of this is about the science. All of this is a political debate about the role of government,â she said in the documentary. These controversies are really about values, not scientific facts, and acknowledging that would allow us to have more truthful and productive debates. What would that look like in practice? Instead of cherry-picking evidence to support a particular view (and insisting that the science points to a desired action), the various sides could lay out the values they are using to assess the evidence. For instance, in Europe, many decisions are guided by the precautionary principle â a system that values caution in the face of uncertainty and says that when the risks are unclear, it should be up to industries to show that their products and processes are not harmful, rather than requiring the government to prove that they are harmful before they can be regulated. By contrast, U.S. agencies tend to wait for strong evidence of harm before issuing regulations. Both approaches have critics, but the difference between them comes down to priorities: Is it better to exercise caution at the risk of burdening companies and perhaps the economy, or is it more important to avoid potential economic downsides even if it means that sometimes a harmful product or industrial process goes unregulated? In other words, under what circumstances do we agree to act on a risk? How certain do we need to be that the risk is real, and how many people would need to be at risk, and how costly is it to reduce that risk? Those are moral questions, not scientific ones, and openly discussing and identifying these kinds of judgment calls would lead to a more honest debate. Science matters, and we need to do it as rigorously as possible. But science canât tell us how risky is too risky to allow products like cigarettes or potentially harmful pesticides to be sold â those are value judgements that only humans can make.
Introduction to Free Fall A free-falling object is an object that is falling under the sole influence of gravity. Any object that is being acted upon only by the force of gravity is said to be in a state of free fall. There are two important motion characteristics that are true of free-falling objects: ⢠Free-falling objects do not encounter air resistance. ⢠All free-falling objects (on Earth) accelerate downwards at a rate of 9.8 m/s/s (often approximated as 10 m/s/s for back-of-the-envelope calculations) Because free-falling objects are accelerating downwards at a rate of 9.8 m/s/s, a ticker tape trace or dot diagram of its motion would depict an acceleration. The dot diagram at the right depicts the acceleration of a free-falling object. The position of the object at regular time intervals - say, every 0.1 second - is shown. The fact that the distance that the object travels every interval of time is increasing is a sure sign that the ball is speeding up as it falls downward. Recall from an earlier lesson, that if an object travels downward and speeds up, then its acceleration is downward. Free-fall acceleration is often witnessed in a physics classroom by means of an ever-popular strobe light demonstration. The room is darkened and a jug full of water is connected by a tube to a medicine dropper. The dropper drips water and the strobe illuminate the falling droplets at a regular rate - say once every 0.2 seconds. Instead of seeing a stream of water free-falling from the medicine dropper, several consecutive drops with increasing separation distance are seen. The pattern of drops resembles the dot diagram shown in the graphic at the right. The Acceleration of Gravity It was learned in the previous part of this lesson that a free-falling object is an object that is falling under the sole influence of gravity. A free-falling object has an acceleration of 9.8 m/s/s, downward (on Earth). This numerical value for the acceleration of a free-falling object is such an important value that it is given a special name. It is known as the acceleration of gravity - the acceleration for any object moving under the sole influence of gravity. A matter of fact, this quantity known as the acceleration of gravity is such an important quantity that physicists have a special symbol to denote it - the symbol g. The numerical value for the acceleration of gravity is most accurately known as 9.8 m/s2. There are slight variations in this numerical value (to the second decimal place) that are dependent primarily upon on altitude. We will occasionally use the approximated value of 10 m/s2 in order to reduce the complexity of the many mathematical tasks that we will perform with this number. By so doing, we will be able to better focus on the conceptual nature of physics without too much of a sacrifice in numerical accuracy. g = 9.8 m/s2, downward Look It Up! Even on the surface of the Earth, there are local variations in the value of the acceleration of gravity (g). These variations are due to latitude, altitude and the local geological structure of the region. Recall from an earlier lesson that acceleration is the rate at which an object changes its velocity. It is the ratio of velocity change to time between any two points in an object's path. To accelerate at 9.8 m/s2 means to change the velocity by 9.8 m/s each second. If the velocity and time for a free-falling object being dropped from a position of rest were tabulated, then one would note the following pattern. Time (s) Velocity (m/s) 0 0 1 - 9.8 2 - 19.6 3 - 29.4 4 - 39.2 5 - 49.0 . Observe that the velocity-time data above reveal that the object's velocity is changing by 9.8 m/s each consecutive second. That is, the free-falling object has an acceleration of approximately 9.8 m/s2. Another way to represent this acceleration of 9.8 m/s2 is to add numbers to our dot diagram that we saw earlier in this lesson. The velocity of the ball is seen to increase as depicted in the diagram at the right. (NOTE: The diagram is not drawn to scale - in two seconds, the object would drop considerably further than the distance from shoulder to toes.) Representing Free Fall by Graphs ⢠Early in Lesson 1 it was mentioned that there are a variety of means of describing the motion of objects. One such means of describing the motion of objects is through the use of graphs - position versus time and velocity vs. time graphs. In this part of Lesson 5, the motion of a free-falling motion will be represented using these two basic types of graphs. Representing Free Fall by Position-Time Graphs A position versus time graph for a free-falling object is shown below. Observe that the line on the graph curves. As learned earlier, a curved line on a position versus time graph signifies an accelerated motion. Since a free-falling object is undergoing an acceleration (g = 9.8 m/s/s), it would be expected that its position-time graph would be curved. A further look at the position-time graph reveals that the object starts with a small velocity (slow) and finishes with a large velocity (fast). Since the slope of any position vs. time graph is the velocity of the object (as learned in Lesson 3), the small initial slope indicates a small initial velocity and the large final slope indicates a large final velocity. Finally, the negative slope of the line indicates a negative (i.e., downward) velocity. Representing Free Fall by Velocity-Time Graphs A velocity versus time graph for a free-falling object is shown below. Observe that the line on the graph is a straight, diagonal line. As learned earlier, a diagonal line on a velocity versus time graph signifies an accelerated motion. Since a free-falling object is undergoing an acceleration (g = 9,8 m/s/s, downward), it would be expected that its velocity-time graph would be diagonal. A further look at the velocity-time graph reveals that the object starts with a zero velocity (as read from the graph) and finishes with a large, negative velocity; that is, the object is moving in the negative direction and speeding up. An object that is moving in the negative direction and speeding up is said to have a negative acceleration (if necessary, review the vector nature of acceleration). Since the slope of any velocity versus time graph is the acceleration of the object (as learned in Lesson 4), the constant, negative slope indicates a constant, negative acceleration. This analysis of the slope on the graph is consistent with the motion of a free-falling object - an object moving with a constant acceleration of 9.8 m/s/s in the downward direction. The Kinematic Equations The goal of this first unit has been to investigate the variety of means by which the motion of objects can be described. The variety of representations that we have investigated includes verbal representations, pictorial representations, numerical representations, and graphical representations (position-time graphs and velocity-time graphs). In Lesson 6, we will investigate the use of equations to describe and represent the motion of objects. These equations are known as kinematic equations. There are a variety of quantities associated with the motion of objects - displacement (and distance), velocity (and speed), acceleration, and time. Knowledge of each of these quantities provides descriptive information about an object's motion. For example, if a car is known to move with a constant velocity of 22.0 m/s, North for 12.0 seconds for a northward displacement of 264 meters, then the motion of the car is fully described. And if a second car is known to accelerate from a rest position with an eastward acceleration of 3.0 m/s2 for a time of 8.0 seconds, providing a final velocity of 24 m/s, East and an eastward displacement of 96 meters, then the motion of this car is fully described. These two statements provide a complete description of the motion of an object. However, such completeness is not always known. It is often the case that only a few parameters of an object's motion are known, while the rest are unknown. For example as you approach the stoplight, you might know that your car has a velocity of 22 m/s, East and is capable of a skidding acceleration of 8.0 m/s2, West. However you do not know the displacement that your car would experience if you were to slam on your brakes and skid to a stop; and you do not know the time required to skid to a stop. In such an instance as this, the unknown parameters can be determined using physics principles and mathematical equations (the kinematic equations). The BIG 4 The kinematic equations are a set of four equations that can be utilized to predict unknown information about an object's motion if other information is known. The equations can be utilized for any motion that can be described as being either a constant velocity motion (an acceleration of 0 m/s/s) or a constant acceleration motion. They can never be used over any time period during which the acceleration is changing. Each of the kinematic equations include four variables. If the values of three of the four variables are known, then the value of the fourth variable can be calculated. In this manner, the kinematic equations provide a useful means of predicting information about an object's motion if other information is known. For example, if the acceleration value and the initial and final velocity values of a skidding car is known, then the displacement of the car and the time can be predicted using the kinematic equations. Lesson 6 of this unit will focus upon the use of the kinematic equations to predict the numerical values of unknown quantities for an object's motion. The four kinematic equations that describe an object's motion are: There are a variety of symbols used in the above equations. Each symbol has its own specific meaning. The symbol d stands for the displacement of the object. The symbol t stands for the time for which the object moved. The symbol a stands for the acceleration of the object. And the symbol v stands for the velocity of the object; a subscript of i after the v (as in vi) indicates that the velocity value is the initial velocity value and a subscript of f (as in vf) indicates that the velocity value is the final velocity value. Each of these four equations appropriately describes the mathematical relationship between the parameters of an object's motion. As such, they can be used to predict unknown information about an object's motion if other information is known. In the next part of Lesson 6 we will investigate the process of doing this. Kinematic Equations and Problem-Solving The four kinematic equations that describe the mathematical relationship between the parameters that describe an object's motion were introduced in the previous part of Lesson 6. The four kinematic equations are: In the above equations, the symbol d stands for the displacement of the object. The symbol t stands for the time for which the object moved. The symbol a stand for the acceleration of the object. And the symbol v stands for the instantaneous velocity of the object; a subscript of i after the v (as in vi) indicates that the velocity value is the initial velocity value and a subscript of f (as in vf) indicates that the velocity value is the final velocity value. Problem-Solving Strategy In this part of Lesson 6 we will investigate the process of using the equations to determine unknown information about an object's motion. The process involves the use of a problem-solving strategy that will be used throughout the course. The strategy involves the following steps: 1. Construct an informative diagram of the physical situation. 2. Identify and list the given information in variable form. 3. Identify and list the unknown information in variable form. 4. Identify and list the equation that will be used to determine unknown information from known information. 5. Substitute known values into the equation and use appropriate algebraic steps to solve for the unknown information. 6. Check your answer to ensure that it is reasonable and mathematically correct. The use of this problem-solving strategy in the solution of the following problem is modeled in Examples A and B below. Example Problem A . Ima Hurryin is approaching a stoplight moving with a velocity of +30.0 m/s. The light turns yellow, and Ima applies the brakes and skids to a stop. If Ima's acceleration is -8.00 m/s2, then determine the displacement of the car during the skidding process. (Note that the direction of the velocity and the acceleration vectors are denoted by a + and a - sign.) The solution to this problem begins by the construction of an informative diagram of the physical situation. This is shown below. The second step involves the identification and listing of known information in variable form. Note that the vf value can be inferred to be 0 m/s since Ima's car comes to a stop. The initial velocity (vi) of the car is +30.0 m/s since this is the velocity at the beginning of the motion (the skidding motion). And the acceleration (a) of the car is given as - 8.00 m/s2. (Always pay careful attention to the + and - signs for the given quantities.) The next step of the strategy involves the listing of the unknown (or desired) information in variable form. In this case, the problem requests information about the displacement of the car. So d is the unknown quantity. The results of the first three steps are shown in the table below. Diagram: Given: Find: vi = +30.0 m/s vf = 0 m/s a = - 8.00 m/s2 d = ?? The next step of the strategy involves identifying a kinematic equation that would allow you to determine the unknown quantity. There are four kinematic equations to choose from. In general, you will always choose the equation that contains the three known and the one unknown variable. In this specific case, the three known variables and the one unknown variable are vf, vi, a, and d. Thus, you will look for an equation that has these four variables listed in it. An inspection of the four equations above reveals that the equation on the top right contains all four variables. vf2 = vi2 + 2 ⢠a ⢠d Once the equation is identified and written down, the next step of the strategy involves substituting known values into the equation and using proper algebraic steps to solve for the unknown information. This step is shown below. (0 m/s)2 = (30.0 m/s)2 + 2 ⢠(-8.00 m/s2) ⢠d 0 m2/s2 = 900 m2/s2 + (-16.0 m/s2) ⢠d (16.0 m/s2) ⢠d = 900 m2/s2 - 0 m2/s2 (16.0 m/s2)*d = 900 m2/s2 d = (900 m2/s2)/ (16.0 m/s2) d = (900 m2/s2)/ (16.0 m/s2) d = 56.3 m The solution above reveals that the car will skid a distance of 56.3 meters. (Note that this value is rounded to the third digit.) The last step of the problem-solving strategy involves checking the answer to assure that it is both reasonable and accurate. The value seems reasonable enough. It takes a car a considerable distance to skid from 30.0 m/s (approximately 65 mi/hr) to a stop. The calculated distance is approximately one-half a football field, making this a very reasonable skidding distance. Checking for accuracy involves substituting the calculated value back into the equation for displacement and insuring that the left side of the equation is equal to the right side of the equation. Indeed it is! Example Problem B Ben Rushin is waiting at a stoplight. When it finally turns green, Ben accelerated from rest at a rate of a 6.00 m/s2 for a time of 4.10 seconds. Determine the displacement of Ben's car during this time period. Once more, the solution to this problem begins by the construction of an informative diagram of the physical situation. This is shown below. The second step of the strategy involves the identification and listing of known information in variable form. Note that the vi value can be inferred to be 0 m/s since Ben's car is initially at rest. The acceleration (a) of the car is 6.00 m/s2. And the time (t) is given as 4.10 s. The next step of the strategy involves the listing of the unknown (or desired) information in variable form. In this case, the problem requests information about the displacement of the car. So d is the unknown information. The results of the first three steps are shown in the table below. Diagram: Given: Find: vi = 0 m/s t = 4.10 s a = 6.00 m/s2 d = ?? The next step of the strategy involves identifying a kinematic equation that would allow you to determine the unknown quantity. There are four kinematic equations to choose from. Again, you will always search for an equation that contains the three known variables and the one unknown variable. In this specific case, the three known variables and the one unknown variable are t, vi, a, and d. An inspection of the four equations above reveals that the equation on the top left contains all four variables. d = vi ⢠t + ½ ⢠a ⢠t2 Once the equation is identified and written down, the next step of the strategy involves substituting known values into the equation and using proper algebraic steps to solve for the unknown information. This step is shown below. d = (0 m/s) ⢠(4.1 s) + ½ ⢠(6.00 m/s2) ⢠(4.10 s)2 d = (0 m) + ½ ⢠(6.00 m/s2) ⢠(16.81 s2) d = 0 m + 50.43 m d = 50.4 m The solution above reveals that the car will travel a distance of 50.4 meters. (Note that this value is rounded to the third digit.) The last step of the problem-solving strategy involves checking the answer to assure that it is both reasonable and accurate. The value seems reasonable enough. A car with an acceleration of 6.00 m/s/s will reach a speed of approximately 24 m/s (approximately 50 mi/hr) in 4.10 s. The distance over which such a car would be displaced during this time period would be approximately one-half a football field, making this a very reasonable distance. Checking for accuracy involves substituting the calculated value back into the equation for displacement and insuring that the left side of the equation is equal to the right side of the equation. Indeed, it is! The two example problems above illustrate how the kinematic equations can be combined with a simple problem-solving strategy to predict unknown motion parameters for a moving object. Provided that three motion parameters are known, any of the remaining values can be determined. In the next part of Lesson 6, we will see how this strategy can be applied to free fall situations. Or if interested, you can try some practice problems and check your answer against the given solutions. Kinematic Equations and Free Fall As mentioned in Lesson 5, a free-falling object is an object that is falling under the sole influence of gravity. That is to say that any object that is moving and being acted upon only be the force of gravity is said to be "in a state of free fall." Such an object will experience a downward acceleration of 9.8 m/s/s. Whether the object is falling downward or rising upward towards its peak, if it is under the sole influence of gravity, then its acceleration value is 9.8 m/s/s. Like any moving object, the motion of an object in free fall can be described by four kinematic equations. The kinematic equations that describe any object's motion are: The symbols in the above equation have a specific meaning: the symbol d stands for the displacement; the symbol t stands for the time; the symbol a stands for the acceleration of the object; the symbol vi stands for the initial velocity value; and the symbol vf stands for the final velocity. Applying Free Fall Concepts to Problem-Solving There are a few conceptual characteristics of free fall motion that will be of value when using the equations to analyze free fall motion. These concepts are described as follows: ⢠An object in free fall experiences an acceleration of -9.8 m/s/s. (The - sign indicates a downward acceleration.) Whether explicitly stated or not, the value of the acceleration in the kinematic equations is -9.8 m/s/s for any freely falling object. ⢠If an object is merely dropped (as opposed to being thrown) from an elevated height, then the initial velocity of the object is 0 m/s. ⢠If an object is projected upwards in a perfectly vertical direction, then it will slow down as it rises upward. The instant at which it reaches the peak of its trajectory, its velocity is 0 m/s. This value can be used as one of the motion parameters in the kinematic equations; for example, the final velocity (vf) after traveling to the peak would be assigned a value of 0 m/s. ⢠If an object is projected upwards in a perfectly vertical direction, then the velocity at which it is projected is equal in magnitude and opposite in sign to the velocity that it has when it returns to the same height. That is, a ball projected vertically with an upward velocity of +30 m/s will have a downward velocity of -30 m/s when it returns to the same height. These four principles and the four kinematic equations can be combined to solve problems involving the motion of free-falling objects. The two examples below illustrate application of free fall principles to kinematic problem-solving. In each example, the problem solving strategy that was introduced earlier in this lesson will be utilized. Example Problem A Luke Autbeloe drops a pile of roof shingles from the top of a roof located 8.52 meters above the ground. Determine the time required for the shingles to reach the ground. The solution to this problem begins by the construction of an informative diagram of the physical situation. This is shown below. The second step involves the identification and listing of known information in variable form. You might note that in the statement of the problem, there is only one piece of numerical information explicitly stated: 8.52 meters. The displacement (d) of the shingles is -8.52 m. (The - sign indicates that the displacement is downward). The remaining information must be extracted from the problem statement based upon your understanding of the above principles. For example, the vi value can be inferred to be 0 m/s since the shingles are dropped (released from rest; see note above). And the acceleration (a) of the shingles can be inferred to be -9.8 m/s2 since the shingles are free-falling (see note above). (Always pay careful attention to the + and - signs for the given quantities.) The next step of the solution involves the listing of the unknown (or desired) information in variable form. In this case, the problem requests information about the time of fall. So t is the unknown quantity. The results of the first three steps are shown in the table below. Diagram: Given: Find: vi = 0.0 m/s d = -8.52 m a = - 9.8 m/s2 t = ?? The next step involves identifying a kinematic equation that allows you to determine the unknown quantity. There are four kinematic equations to choose from. In general, you will always choose the equation that contains the three known and the one unknown variable. In this specific case, the three known variables and the one unknown variable are d, vi, a, and t. Thus, you will look for an equation that has these four variables listed in it. An inspection of the four equations above reveals that the equation on the top left contains all four variables. d = vi ⢠t + ½ ⢠a ⢠t2 Once the equation is identified and written down, the next step involves substituting known values into the equation and using proper algebraic steps to solve for the unknown information. This step is shown below. -8.52 m = (0 m/s) ⢠(t) + ½ ⢠(-9.8 m/s2) ⢠(t)2 -8.52 m = (0 m) *(t) + (-4.9 m/s2) ⢠(t)2 -8.52 m = (-4.9 m/s2) ⢠(t)2 (-8.52 m)/(-4.9 m/s2) = t2 1.739 s2 = t2 t = 1.32 s The solution above reveals that the shingles will fall for a time of 1.32 seconds before hitting the ground. (Note that this value is rounded to the third digit.) The last step of the problem-solving strategy involves checking the answer to assure that it is both reasonable and accurate. The value seems reasonable enough. The shingles are falling a distance of approximately 10 yards (1 meter is pretty close to 1 yard); it seems that an answer between 1 and 2 seconds would be highly reasonable. The calculated time easily falls within this range of reasonability. Checking for accuracy involves substituting the calculated value back into the equation for time and insuring that the left side of the equation is equal to the right side of the equation. Indeed it is! Example Problem B Rex Things throws his mother's crystal vase vertically upwards with an initial velocity of 26.2 m/s. Determine the height to which the vase will rise above its initial height. Once more, the solution to this problem begins by the construction of an informative diagram of the physical situation. This is shown below. The second step involves the identification and listing of known information in variable form. You might note that in the statement of the problem, there is only one piece of numerical information explicitly stated: 26.2 m/s. The initial velocity (vi) of the vase is +26.2 m/s. (The + sign indicates that the initial velocity is an upwards velocity). The remaining information must be extracted from the problem statement based upon your understanding of the above principles. Note that the vf value can be inferred to be 0 m/s since the final state of the vase is the peak of its trajectory (see note above). The acceleration (a) of the vase is -9.8 m/s2 (see note above). The next step involves the listing of the unknown (or desired) information in variable form. In this case, the problem requests information about the displacement of the vase (the height to which it rises above its starting height). So d is the unknown information. The results of the first three steps are shown in the table below. Diagram: Given: Find: vi = 26.2 m/s vf = 0 m/s a = -9.8 m/s2 d = ?? The next step involves identifying a kinematic equation that would allow you to determine the unknown quantity. There are four kinematic equations to choose from. Again, you will always search for an equation that contains the three known variables and the one unknown variable. In this specific case, the three known variables and the one unknown variable are vi, vf, a, and d. An inspection of the four equations above reveals that the equation on the top right contains all four variables. vf2 = vi2 + 2 ⢠a ⢠d Once the equation is identified and written down, the next step involves substituting known values into the equation and using proper algebraic steps to solve for the unknown information. This step is shown below. (0 m/s)2 = (26.2 m/s)2 + 2 â˘(-9.8m/s2) â˘d 0 m2/s2 = 686.44 m2/s2 + (-19.6 m/s2) â˘d (-19.6 m/s2) ⢠d = 0 m2/s2 -686.44 m2/s2 (-19.6 m/s2) ⢠d = -686.44 m2/s2 d = (-686.44 m2/s2)/ (-19.6 m/s2) d = 35.0 m The solution above reveals that the vase will travel upwards for a displacement of 35.0 meters before reaching its peak. (Note that this value is rounded to the third digit.) The last step of the problem-solving strategy involves checking the answer to assure that it is both reasonable and accurate. The value seems reasonable enough. The vase is thrown with a speed of approximately 50 mi/hr (merely approximate 1 m/s to be equivalent to 2 mi/hr). Such a throw will never make it further than one football field in height (approximately 100 m), yet will surely make it past the 10-yard line (approximately 10 meters). The calculated answer certainly falls within this range of reasonability. Checking for accuracy involves substituting the calculated value back into the equation for displacement and insuring that the left side of the equation is equal to the right side of the equation. Indeed, it is! Kinematic equations provide a useful means of determining the value of an unknown motion parameter if three motion parameters are known. In the case of a free-fall motion, the acceleration is often known. And in many cases, another motion parameter can be inferred through a solid knowledge of some basic kinematic principles.
Introduction to Hedging Instruments: Forwards, Futures, Options, and Swaps Hedging instruments are financial tools used by businesses and investors to mitigate risk. These instruments help protect against adverse price movements in assets such as commodities, currencies, interest rates, or securities. The four main hedging instruments are forwards, futures, options, and swaps. 1. Forwards A forward contract is a customised agreement between two parties to buy or sell an asset at a predetermined price on a specified future date. Key Characteristics: Over-the-counter (OTC): Traded directly between parties, not on an exchange. Customisation: Can be tailored to suit the needs of the parties involved. Settlement: Occurs at the end of the contract, which may involve physical delivery or cash settlement. Risk: Forwards carry counter-party risk, as there is a possibility one party may default. Example: A company that needs to import raw materials in six months may enter into a forward contract to lock in the current price, avoiding the risk of price increases. 2. Futures A futures contract is similar to a forward, but it is standardised and traded on an exchange. This standardisation eliminates counter-party risk. Key Characteristics: Standardised: Contract size, expiration, and other terms are fixed by the exchange. Mark-to-market: Gains and losses are settled daily. Liquidity: Futures are highly liquid because they are traded on exchanges. Regulation: As they are traded on formal exchanges, they are more regulated than forwards. Example: A wheat farmer may sell futures contracts to hedge against a possible decline in wheat prices before harvest. 3. Options Options provide the right, but not the obligation, to buy or sell an asset at a specified price on or before a certain date. There are two types of options: call options and put options. Call Option: Gives the holder the right to buy an asset at a predetermined price. Put Option: Gives the holder the right to sell an asset at a predetermined price. Key Characteristics: Premium: The buyer pays a premium upfront to obtain the option. Limited Risk: The maximum loss is limited to the premium paid. Flexibility: Options can be used for speculative or hedging purposes. Example: An investor holding stocks may buy a put option to protect against potential declines in the stock's price. 4. Swaps A swap is a contract in which two parties agree to exchange cash flows or liabilities over a specific period. The most common types are interest rate swaps and currency swaps. Key Characteristics: Customizable: Like forwards, swaps are often tailored to meet the needs of the parties involved. Counterparty Risk: Swaps are typically OTC instruments, exposing parties to default risk. Common Uses: Used to manage interest rate risk or currency risk. Example: A company with a variablerate loan may enter into an interest rate swap to exchange its variable payments for fixedrate payments, thus locking in stable costs. Hedging instruments are essential for managing financial risk in volatile markets. Each instrument serves different purposes, with varying levels of complexity, risk, and customization. Whether through forwards, futures, options, or swaps, businesses can better plan for the future by reducing exposure to uncertain price fluctuations. Hedging Strategies for Market Risk, Credit Risk, and Currency Risk 1. Hedging Strategies for Market Risk Market risk (also known as systematic risk) arises from fluctuations in asset prices, such as stocks, bonds, commodities, and interest rates, due to economic factors or market volatility. Key Hedging Instruments for Market Risk: Derivatives (Options, Futures, and Forwards): These instruments allow investors to hedge against unfavorable price movements in stocks, commodities, or interest rates. Example: An investor holding a large stock portfolio might buy a put option to protect against a potential market downturn. If the market declines, the put option increases in value, offsetting losses in the portfolio. Short Selling: Investors can sell borrowed assets with the expectation of buying them back at a lower price, profiting from the decline. Example: A fund manager expecting a market decline may short sell stocks to hedge a portfolio against losses. Common Hedging Strategies: Portfolio Diversification: Reducing market risk by spreading investments across various asset classes (stocks, bonds, commodities) and sectors. Using Index Futures: Large portfolios can be hedged using index futures that track the performance of the overall market. If the market declines, profits from the short position in the futures contract will offset losses in the portfolio. Risk Parity: Allocating assets based on the level of risk rather than the dollar amount invested, balancing risk exposure across asset classes. 2. Hedging Strategies for Credit Risk Credit risk refers to the possibility that a borrower will default on a debt obligation. This is especially important for banks, lenders, and institutions dealing with bonds and loans. Key Hedging Instruments for Credit Risk: Credit Default Swaps (CDS): A financial derivative where the buyer of a CDS pays a premium to the seller in exchange for protection against a default on a loan or bond. Example: A bank holding corporate bonds can buy a CDS to ensure they are compensated if the issuing company defaults. Collateralised Debt Obligations (CDOs): These instruments pool together various debt instruments and allow risk to be distributed among multiple investors. Credit Insurance: Companies may use insurance to protect against the risk of a customer defaulting on payments. Common Hedging Strategies: Diversification of Loan Portfolio: Spreading out credit exposures across various industries, geographies, and borrower profiles reduces the overall risk of default. Tightening Lending Standards: Limiting exposure to highrisk borrowers by implementing stringent credit assessments. AssetBacked Securities: Banks can sell loans or bonds packaged as assetbacked securities to reduce their exposure to credit risk. 3. Hedging Strategies for Currency Risk Currency risk (or exchange rate risk) arises from fluctuations in foreign exchange rates, which can affect companies involved in international trade or with investments in foreign countries. Key Hedging Instruments for Currency Risk: Forward Contracts: A firm agrees to exchange a specified amount of currency at a predetermined exchange rate on a future date. Example: A U.S. exporter expecting payment in euros might enter into a forward contract to sell euros and lock in a favorable exchange rate. Currency Options: These give the right, but not the obligation, to buy or sell currency at a specific price. Example: A U.S.based company buying goods from Japan might buy a call option on the yen to hedge against the risk of yen appreciation. Currency Swaps: Two parties exchange interest payments and principal in different currencies to hedge against exchange rate fluctuations. Common Hedging Strategies: Natural Hedging: Companies can offset currency risk by balancing foreign revenue with costs in the same currency. For example, if a company generates revenue in euros, it can also incur expenses in euros, reducing exposure to exchange rate fluctuations. Multi-Currency Invoicing: Firms can invoice in their home currency, shifting the currency risk to the buyer. Currency Diversification: Holding a diversified basket of currencies can reduce exposure to large fluctuations in any one currency. Effective hedging strategies are crucial for managing various types of risks in financial markets. Market risk can be managed using instruments like futures and options, while credit risk can be mitigated through diversification and credit derivatives. Currency risk, often faced by multinational firms, can be hedged using forward contracts, options, or swaps. Each strategy helps firms and investors protect their portfolios, ensure financial stability, and reduce the impact of adverse movements in the financial markets. Portfolio Risk Management Techniques: Diversification, Asset Allocation, and Risk Budgeting Managing risk is a fundamental aspect of portfolio management. Investors use various techniques to control and reduce the risks inherent in investing. Three key techniques used in portfolio risk management are diversification, asset allocation, and risk budgeting. Each of these techniques helps in mitigating potential losses while aiming to achieve the desired return. 1. Diversification Diversification is a risk management strategy that involves spreading investments across different assets, sectors, or geographic regions to reduce exposure to any single risk. The idea is that different assets perform differently under various market conditions, so losses in one investment can be offset by gains in others. Key Benefits of Diversification: Reduction of Unsystematic Risk: Unsystematic risk, which is unique to a specific company or industry, can be reduced by holding a variety of investments that respond differently to market conditions. Improved Stability: A diversified portfolio is less volatile, as the negative performance of one asset can be balanced by the positive performance of others. Methods of Diversification: Across Asset Classes: Investing in a mix of asset classes such as stocks, bonds, commodities, and real estate. Example: A portfolio with 60% equities, 30% bonds, and 10% commodities is more diversified than one solely consisting of stocks. Within Asset Classes: Diversifying within a single asset class (e.g., holding stocks from different sectors like technology, healthcare, and energy). Geographic Diversification: Investing in assets across various countries or regions to mitigate country-specific risks. Example: Holding U.S. stocks along with emerging market equities can reduce risks related to a downturn in one country's economy. 2. Asset Allocation Asset allocation refers to the process of dividing investments among different asset classes (such as stocks, bonds, and cash) to align with an investor's risk tolerance, time horizon, and financial goals. Asset allocation plays a crucial role in portfolio risk management by determining the overall risk-return profile of the portfolio. Key Elements of Asset Allocation: Strategic Asset Allocation: A longterm approach that involves setting target allocations for different asset classes based on financial goals and risk tolerance. Example: A young investor with a longterm horizon might allocate 70% to stocks, 20% to bonds, and 10% to cash. Tactical Asset Allocation: A more active approach that involves adjusting the asset mix in response to short-term market conditions. Example: If the investor expects an economic downturn, they might temporarily reduce exposure to equities and increase exposure to bonds. Types of Asset Allocation Models: Conservative: Focuses on preserving capital with a larger allocation to bonds and cash (e.g., 20% stocks, 80% bonds). Balanced: A moderate risk approach with an equal focus on growth and income (e.g., 50% stocks, 50% bonds). Aggressive: Targets higher returns by investing predominantly in equities, accepting higher risk (e.g., 80% stocks, 20% bonds). Example of Asset Allocation: A 40 year old investor with moderate risk tolerance may allocate their portfolio as follows: 50% equities, 40% bonds, and 10% in alternative investments such as real estate or commodities. The equities provide growth potential, while the bonds and alternative assets offer stability and income. 3. Risk Budgeting Risk budgeting is a method of allocating risk across different components of a portfolio, rather than focusing solely on returns. The goal is to optimise the portfolioâs risk-return profile by distributing risk in a way that aligns with the investorâs objectives and risk tolerance. Key Concepts of Risk Budgeting: Risk Contribution: Each asset class or investment in the portfolio contributes a certain amount of risk (measured by metrics such as volatility or Value at Risk). Risk budgeting ensures that no single asset class dominates the overall risk of the portfolio. Example: A portfolio may contain 60% stocks and 40% bonds, but if the stocks are highly volatile, they may contribute 90% of the portfolio's risk. Target Risk: Investors set a maximum acceptable level of risk (e.g., a portfolio volatility of 10%) and allocate investments so that the total risk remains within this target. Techniques in Risk Budgeting: Risk Parity: Allocates risk evenly across asset classes, rather than allocating capital based solely on return expectations. Example: In a risk-parity portfolio, both bonds and stocks might be balanced in such a way that they contribute equally to the overall portfolio risk, even though the dollar investment in bonds may be larger due to their lower volatility. Value at Risk (VaR): This technique measures the potential loss in a portfolio over a specific time period, under normal market conditions, at a given confidence level. The risk budget ensures that the potential loss stays within acceptable limits. Example of Risk Budgeting: An investor targets an overall portfolio risk of 8% volatility. After analyzing the risk contribution of each asset class, they determine that equities, which currently make up 60% of the portfolio, contribute 70% of the risk. To adhere to the risk budget, the investor may reduce their equity exposure and increase their allocation to bonds or other less volatile assets. Diversification, asset allocation, and risk budgeting are complementary techniques used in portfolio risk management. Diversification reduces unsystematic risk by spreading investments across various assets. Asset allocation ensures that investments align with an investor's goals and risk tolerance. Risk budgeting focuses on managing the contribution of risk from each asset class to create a balanced and efficient portfolio. Together, these strategies help investors achieve a balance between risk and return, ensuring longterm portfolio stability. Risk Mitigation Through Insurance, Securitisation, and Other Financial Engineering Techniques Risk mitigation is a core objective in financial management, and various strategies can be employed to reduce or manage risks. Three major approaches are insurance, securitisation, and financial engineering techniques. Each of these methods helps firms and individuals transfer, reduce, or eliminate certain financial risks. 1. Insurance as a Risk Mitigation Tool Insurance is a traditional risk transfer method that protects against financial losses by shifting the risk to an insurance company in exchange for premium payments. It is widely used to mitigate various forms of risk, such as operational, liability, and property risks. Key Aspects of Insurance for Risk Mitigation: Risk Transfer: The insurer takes on the risk in exchange for a premium, thus protecting the insured party from unexpected financial losses. Indemnity: In the event of a loss, the insurance policy compensates the insured based on the terms of the contract. Customisable Coverage: Insurance policies can be tailored to address specific risks, such as property damage, business interruption, liability, or cyber risks. Types of Insurance for Businesses: Property and Casualty Insurance: Covers physical assets like buildings, machinery, and inventory from risks like fire, theft, or natural disasters. Liability Insurance: Protects businesses against legal liabilities arising from accidents, negligence, or professional errors. Business Interruption Insurance: Compensates for lost income if a business has to halt operations due to unforeseen events. Credit Insurance: Shields companies from losses due to the nonpayment of trade receivables. 2. Securitisation as a Risk Mitigation Technique Securitisation is a financial engineering process that involves pooling various financial assets (such as loans, mortgages, or receivables) and converting them into marketable securities. This process allows firms to transfer risk to investors, thereby reducing their exposure. Key Elements of Securitisation: Risk Transfer: By securitising assets, companies can transfer the risk of default or nonpayment to investors who purchase the securities. Liquidity Creation: Securitisation converts illiquid assets (like mortgages or loans) into liquid, tradeable securities, improving cash flow for the originating firm. Diversification of Risk: Pooling assets with different risk profiles reduces the impact of individual defaults, spreading the risk across multiple investors. Common Forms of Securitisation: MortgageBacked Securities (MBS): Pools of mortgages are bundled and sold as securities to investors, transferring the risk of mortgage defaults. Example: A bank that issues home loans can bundle those loans into MBS and sell them to investors, transferring the credit risk of potential defaults. Asset-Backed Securities (ABS): Similar to MBS, but backed by other types of assets like credit card receivables, auto loans, or student loans. Collateralised Debt Obligations (CDOs): Structured financial products that pool different types of debt, such as loans and bonds, and sell them as securities with varying risk levels. Example: A bank may issue a portfolio of auto loans and then pool these loans into an assetbacked security (ABS). The ABS is sold to investors, who take on the risk of loan defaults. By securitising the loans, the bank reduces its exposure to credit risk and generates immediate cash flow. 3. Financial Engineering Techniques for Risk Mitigation Financial engineering involves the use of complex financial instruments, derivatives, and structured products to manage or mitigate financial risks. These techniques allow firms to hedge against specific risks, optimize capital structure, and improve financial stability. Common Financial Engineering Techniques: Derivatives: Financial instruments like futures, forwards, options, and swaps are used to hedge against price fluctuations, interest rate changes, or currency movements. Example: A company with significant foreign exchange exposure may use currency forwards or options to hedge against exchange rate fluctuations, ensuring predictable cash flows. Options and Futures: Options: Provides the right (but not the obligation) to buy or sell an asset at a predetermined price, allowing firms to hedge against unfavorable price movements. Example: An airline company can buy options on jet fuel to hedge against rising fuel prices. Futures: Standardized contracts to buy or sell an asset at a set price on a future date, commonly used to hedge commodities or financial assets. Example: A wheat producer may use futures contracts to lock in a favorable price for its crop, hedging against a potential price drop. Swaps: These involve the exchange of cash flows between two parties, often used to manage interest rate risk or currency risk. Interest Rate Swaps: Firms can exchange floatingrate interest payments for fixedrate payments to hedge against rising interest rates. Currency Swaps: Used to hedge exchange rate risk in crossborder transactions by exchanging principal and interest payments in different currencies. Example: A company with a variablerate loan may enter into an interest rate swap to exchange its variable payments for fixedrate payments, locking in stable costs. Structured Products: These are customised financial instruments designed to achieve specific riskreturn objectives. They often combine derivatives with other securities to create tailored risk exposures. Example: A structured note that combines a bond with an embedded option, offering downside protection while allowing for potential upside linked to the performance of an equity index. Credit Derivatives: Tools like credit default swaps (CDS) allow investors to transfer credit risk to other parties. Example: A bondholder worried about a companyâs potential default may purchase a CDS, which pays out in case of a default event. Example: A company may issue a bond with an embedded call option, allowing it to repurchase the bond if interest rates decline. This financial engineering tool enables the company to mitigate the risk of rising interest rates, reducing future borrowing costs. Risk mitigation through insurance, securitisation, and financial engineering offers businesses a variety of tools to manage and transfer risks. Insurance allows for the direct transfer of risk to an insurer, while securitisation helps companies offload risk by packaging and selling assets as securities. Financial engineering techniques, including derivatives, swaps, and structured products, provide sophisticated ways to hedge market, interest rate, and currency risks. Each approach helps organizations improve financial stability, enhance liquidity, and manage potential losses in a volatile market environment.
Covalent Molecules and Compounds Just as an atom is the simplest unit that has the fundamental chemical properties of an element, a molecule is the simplest unit that has the fundamental chemical properties of a covalent compound. Some pure elements exist as covalent molecules. Hydrogen, nitrogen, oxygen, and the halogens occur naturally as the diatomic (âtwo atomsâ) molecules H2, N2, O2, F2, Cl2, Br2, and I2 (part (a) in Figure 3.1.1). Similarly, a few pure elements exist as polyatomic (âmany atomsâ) molecules, such as elemental phosphorus and sulfur, which occur as P4 and S8 (part (b) in Figure 3.1.1). Each covalent compound is represented by a molecular formula, which gives the atomic symbol for each component element, in a prescribed order, accompanied by a subscript indicating the number of atoms of that element in the molecule. The subscript is written only if the number of atoms is greater than 1. For example, water, with two hydrogen atoms and one oxygen atom per molecule, is written as H2O. Similarly, carbon dioxide, which contains one carbon atom and two oxygen atoms in each molecule, is written as CO2. Covalent compounds that predominantly contain carbon and hydrogen are called organic compounds. The convention for representing the formulas of organic compounds is to write carbon first, followed by hydrogen and then any other elements in alphabetical order (e.g., CH4O is methyl alcohol, a fuel). Compounds that consist primarily of elements other than carbon and hydrogen are called inorganic compounds; they include both covalent and ionic compounds. In inorganic compounds, the component elements are listed beginning with the one farthest to the left in the periodic table, as in CO2 or SF6. Those in the same group are listed beginning with the lower element and working up, as in ClF. By convention, however, when an inorganic compound contains both hydrogen and an element from groups 13â15, hydrogen is usually listed last in the formula. Examples are ammonia (NH3) and silane (SiH4). Compounds such as water, whose compositions were established long before this convention was adopted, are always written with hydrogen first: Water is always written as H2O, not OH2. The conventions for inorganic acids, such as hydrochloric acid (HCl) and sulfuric acid (H2SO4), are described elswhere. Note! For organic compounds: write C first, then H, and then the other elements in alphabetical order. For molecular inorganic compounds: start with the element at far left in the periodic table; list elements in same group beginning with the lower element and working up. Write the molecular formula of each compound. a. The phosphorus-sulfur compound that is responsible for the ignition of so-called strike anywhere matches has 4 phosphorus atoms and 3 sulfur atoms per molecule. b. Ethyl alcohol, the alcohol of alcoholic beverages, has 1 oxygen atom, 2 carbon atoms, and 6 hydrogen atoms per molecule. c. Freon-11, once widely used in automobile air conditioners and implicated in damage to the ozone layer, has 1 carbon atom, 3 chlorine atoms, and 1 fluorine atom per molecule. Solution: a. ⢠A The molecule has 4 phosphorus atoms and 3 sulfur atoms. Because the compound does not contain mostly carbon and hydrogen, it is inorganic. ⢠B Phosphorus is in group 15, and sulfur is in group 16. Because phosphorus is to the left of sulfur, it is written first. ⢠C Writing the number of each kind of atom as a right-hand subscript gives P4S3 as the molecular formula. b. ⢠A Ethyl alcohol contains predominantly carbon and hydrogen, so it is an organic compound. ⢠B The formula for an organic compound is written with the number of carbon atoms first, the number of hydrogen atoms next, and the other atoms in alphabetical order: CHO. ⢠C Adding subscripts gives the molecular formula C2H6O. c. ⢠A Freon-11 contains carbon, chlorine, and fluorine. It can be viewed as either an inorganic compound or an organic compound (in which fluorine has replaced hydrogen). The formula for Freon-11 can therefore be written using either of the two conventions. ⢠B According to the convention for inorganic compounds, carbon is written first because it is farther left in the periodic table. Fluorine and chlorine are in the same group, so they are listed beginning with the lower element and working up: CClF. Adding subscripts gives the molecular formula CCl3F. ⢠C We obtain the same formula for Freon-11 using the convention for organic compounds. The number of carbon atoms is written first, followed by the number of hydrogen atoms (zero) and then the other elements in alphabetical order, also giving CCl3F. Write the molecular formula for each compound. a. Nitrous oxide, also called âlaughing gas,â has 2 nitrogen atoms and 1 oxygen atom per molecule. Nitrous oxide is used as a mild anesthetic for minor surgery and as the propellant in cans of whipped cream. b. Sucrose, also known as cane sugar, has 12 carbon atoms, 11 oxygen atoms, and 22 hydrogen atoms. c. Sulfur hexafluoride, a gas used to pressurize âunpressurizedâ tennis balls and as a coolant in nuclear reactors, has 6 fluorine atoms and 1 sulfur atom per molecule. Answer: a. N2O b. C12H22O11 c. SF6. Ionic Compounds The substances described in the preceding discussion are composed of molecules that are electrically neutral; that is, the number of positively-charged protons in the nucleus is equal to the number of negatively-charged electrons. In contrast, ions are atoms or assemblies of atoms that have a net electrical charge. Ions that contain fewer electrons than protons have a net positive charge and are called cations. Conversely, ions that contain more electrons than protons have a net negative charge and are called anions. Ionic compounds contain both cations and anions in a ratio that results in no net electrical charge. Note! Ionic compounds contain both cations and anions in a ratio that results in zero electrical charge.An ionic compound that contains only two elements, one present as a cation and one as an anion, is called a binary ionic compound. One example is MgCl2, a coagulant used in the preparation of tofu from soybeans. For binary ionic compounds, the subscripts in the empirical formula can also be obtained by crossing charges: use the absolute value of the charge on one ion as the subscript for the other ion. This method is shown schematically as follows: Crossing charges. One method for obtaining subscripts in the empirical formula is by crossing charges. When crossing charges, it is sometimes necessary to reduce the subscripts to their simplest ratio to write the empirical formula. Consider, for example, the compound formed by Mg2+ and O2â. Using the absolute values of the charges on the ions as subscripts gives the formula Mg2O2:Polyatomic Ions Polyatomic ions are groups of atoms that bear net electrical charges, although the atoms in a polyatomic ion are held together by the same covalent bonds that hold atoms together in molecules. Just as there are many more kinds of molecules than simple elements, there are many more kinds of polyatomic ions than monatomic ions. Two examples of polyatomic cations are the ammonium (NH4+) and the methylammonium (CH3NH3+) ions. P. The method used to predict the empirical formulas for ionic compounds that contain monatomic ions can also be used for compounds that contain polyatomic ions. The overall charge on the cations must balance the overall charge on the anions in the formula unit. Thus, K+ and NO3â ions combine in a 1:1 ratio to form KNO3 (potassium nitrate or saltpeter), a major ingredient in black gunpowder. Similarly, Ca2+ and SO42â form CaSO4 (calcium sulfate), which combines with varying amounts of water to form gypsum and plaster of Paris. The polyatomic ions NH4+ and NO3â form NH4NO3 (ammonium nitrate), a widely used fertilizer and, in the wrong hands, an explosive. One example of a compound in which the ions have charges of different magnitudes is calcium phosphate, which is composed of Ca2+ and PO43â ions; it is a major component of bones. The compound is electrically neutral because the ions combine in a ratio of three Ca2+ ions [3(+2) = +6] for every two ions [2(â3) = â6], giving an empirical formula of Ca3(PO4)2; the parentheses around PO4 in the empirical formula indicate that it is a polyatomic ion. Writing the formula for calcium phosphate as Ca3P2O8 gives the correct number of each atom in the formula unit, but it obscures the fact that the compound contains readily identifiable PO43â ions.Summary ⢠There are two fundamentally different kinds of chemical bonds (covalent and ionic) that cause substances to have very different properties. ⢠The composition of a compound is represented by an empirical or molecular formula, each consisting of at least one formula unit.Contributors The atoms in chemical compounds are held together by attractive electrostatic interactions known as chemical bonds. Ionic compounds contain positively and negatively charged ions in a ratio that results in an overall charge of zero. The ions are held together in a regular spatial arrangement by electrostatic forces. Most covalent compounds consist of molecules, groups of atoms in which one or more pairs of electrons are shared by at least two atoms to form a covalent bond. The atoms in molecules are held together by the electrostatic attraction between the positively charged nuclei of the bonded atoms and the negatively charged electrons shared by the nuclei. The molecular formula of a covalent compound gives the types and numbers of atoms present. Compounds that contain predominantly carbon and hydrogen are called organic compounds, whereas compounds that consist primarily of elements other than carbon and hydrogen are inorganic compounds. Diatomic molecules contain two atoms, and polyatomic molecules contain more than two. A structural formula indicates the composition and approximate structure and shape of a molecule. Single bonds, double bonds, and triple bonds are covalent bonds in which one, two, and three pairs of electrons, respectively, are shared between two bonded atoms. Atoms or groups of atoms that possess a net electrical charge are called ions; they can have either a positive charge (cations) or a negative charge (anions). Ions can consist of one atom (monatomic ions) or several (polyatomic ions). The charges on monatomic ions of most main group elements can be predicted from the location of the element in the periodic table. Ionic compounds usually form hard crystalline solids with high melting points. Covalent molecular compounds, in contrast, consist of discrete molecules held together by weak intermolecular forces and can be gases, liquids, or solids at room temperature and pressure. An empirical formula gives the relative numbers of atoms of the elements in a compound, reduced to the lowest whole numbers. The formula unit is the absolute grouping represented by the empirical formula of a compound, either ionic or covalent. Empirical formulas are particularly useful for describing the composition of ionic compounds, which do not contain readily identifiable molecules. Some ionic compounds occur as hydrates, which contain specific ratios of loosely bound water molecules called waters of hydration.
To understand melody in music, think about some music youâre familiar with. If you were asked to hum it, what would that sound like? The part of the music that youâd hum is the melody. Itâs the main thread of sound that your brain tracks and holds onto when youâre listening to music. In vocal music, the melody is sung by the lead singer. Other vocalists can provide harmony and instruments can add accompaniment, but the melody is the star of the show.What are the characteristics of melody in music? How do you describe a melody in music? A melody needs to have two things. The first is a sequence of notes, or pitches, which range from high to low. The second is rhythm, which is the timing and duration of each note. These two simple elements can create an incredible variety of combinations. Even though a melody only consists of one note at a time, it can convey so much energy and emotion. Melodies can be fast and sparkly, like âThe Flight of the Bumblebee.â They can be slow and majestic, like âFinlandia.â They might be sweeping and graceful, like a Strauss waltz. Or they can be fun and exciting, like your favorite pop tunes that you love to sing along with. Melodies often tell you a lot about where a piece of music comes from. Itâs easy to recognize and identify melodies from different folk traditions such as the Japanese folk song âSakuraâ or the Irish tune âStar of the County Down.â Learn how to play your favorite melodies on piano, and more! Sign up now. What is melody in music? Here are some examples. Here is the famous melody for the song âLean on Meâ written out on a staff. Notice the way that the notes move up, down, and then repeat. What is melody in music? Example of Lean On Me notes on treble staff. A melody all by itself is great, but music can be even more fun when thereâs an accompaniment. Here are a few bars of âLean on Meâ with the accompaniment written out. As you listen to this song, notice how the accompaniment has a very similar rhythm and movement to the melody. Then thereâs that one note in the bass line that comes along every measure with its own rhythm, which adds some extra energy and movement to the song. What makes a good melody? When you create a melody, there are four types of movement you can use: Repeat (same note) Step (up or down) Skip (up or down) Leap (up or down) Stepping and repeating are the most common types of melodic motion, and this makes a melody easier to sing. Most âhummableâ tunes use steps and repeats almost exclusively. This kind of melody is called conjunct. Beethovenâs âOde to Joy,â one of the most famous melodies of all time.Skips and leaps are generally more sparing in melodies, but when thoughtfully placed they can have a powerful emotional impact. Tunes with a lot of leaps are called disjunct. Listen to Sarah Brightman sing All I Ask of You from The Phantom of the Opera starting at 0:39. This is a very disjunct melody, and challenging to sing. Great melodies also incorporate patterns that blend unity, repetition, and contrast. Our ears love patterns, but they also love novelty and growth. A good melody incorporates all of these elements. For example, listen to John Williamâs âPrincess Leia Theme.â Can you hear the repeated pattern in the melody that gradually moves higher as the theme progresses? Now listen to the way it changes and develops into something that fits with what came before but sounds new at the same time. This is some great melodic writing! Can melody exist without rhythm? There is no way for a melody to exist without rhythm. Even if your melody only has one note, that note has a duration, and thatâs the rhythm. If your melody has two notes, how long those notes last and how much time passes between hearing them is also a rhythm. A melody in music can often be recognized even when itâs performed with different rhythms. This frequently happens in live performances of pop, rock, and jazz, in which singers typically improvise slight rhythmic differences with each performance. No two renditions are exactly the same, and this constant reinterpretation keeps the music fresh. How to make a melody for a song on piano Creating your own melodies on the piano is easy and fun! There are so many ways you can discover a melody all your own. Here are a few ideas. Get some inspiration from the world around you. What can you hear right now? A clock ticking? A bird song? A car passing by your house? See if you can find some notes on the piano that imitate the sounds you hear. Think of a feeling youâd like to put into a melody. What are some ways you could make a string of notes sound happy, sad, angry, or maybe just thoughtful. Choose a line from a poem you like, or write your own. Read it out loud and put some feeling into it. Did your voice rise and fall in pitch as you were reading? Now go to the piano, start on any note you like, and try to imitate what happened when you read. Go up when your voice naturally went up, go down when your voice naturally went down. How did that sound? Now you have the perfect melody to go with those words. Too many keys on the piano? The truth is, most melodies use only a limited number of different notes. Try creating a melody using only the black keys. These form whatâs called a pentatonic scale. Itâs used in a lot of folk music traditions around the world and can be a great place to start if you want to create your own melodies. Remember, when you create your melody, keep it simple. Use repeated notes and steps, but add a few skips to keep things interesting. One tip about leaps: when you do put in a big leap, try doubling back and filling in the empty space you leaped over. This keeps the melody self-contained and easier to sing. Also, see if you can use the same patterns of notes and rhythms to give the melody unity, but also change those patterns to give it variety. There is no right or wrong way to create your own music. Keep trying combinations of notes and rhythms until you find something that you like. How many bars and notes are in a melody? Many types of music tend to have a prescribed number of bars, or measures. This will vary widely between different genres, and creates an overall sense of musical structure. If youâre writing a pop song, a verse will usually have between eight and sixteen bars. The prechorus that follows often has just four bars, and this âforeshorteningâ creates a sense of acceleration, driving the listener toward the chorus. The number of notes can also vary widely. A melody in music needs at least two notes, and a long and complex one can have hundreds or even thousands of notes. What is a countermelody in music? How many melodies should a song have? A counter melody is a melodic line that interacts with the primary melody as an independent but supportive voice. A great example of this is the song âWe Donât Talk about Bruno.â Each character sings their own melody during the piece, but these melodies all combine at the end as countermelodies. This produces a musical texture known as counterpoint. The same thing happens in âOne Day Moreâ from Les Miserables. The different melodies are first sung separately, but end up being combined in a splendid, complex texture that leads the music to its thrilling conclusion. The difference between a countermelody and regular harmony is that harmony usually supports the rhythms of the melody. A countermelody will move more independently, with different rhythms from those of the melody, and will often sound âmelodicâ when sung or played all by itself. A melodic song should have one main melody. This is the part that the lead voice sings. Itâs usually in the spotlight, and will be the most memorable part of the music. Anything else is either harmony, countermelody, or accompaniment. Does all music have to have a melody? A piece of music doesnât have to have a melody. There are many different kinds of music without melody. For example, a lot of music played on percussion instruments wonât have a melody. Listen to this example of Tahitian drumming. This is some great music, exciting and fun to listen to, but youâd have a hard time humming it. Itâs music, but it doesnât have a melody. Rap music is another style of music where there doesnât have to be a melody. In rap, words are chanted rather than sung. The performer will raise and lower the pitch of their voice for emphasis, but itâs the rhythm of the words that creates most of the music. Music can even lack any melody, at least in some sections. Listen to the opening chords of âDuel of the Fates.â This choral passage is all about harmony, with little rhythmic variance or sense of melody. But it makes an effective contrast with the next section, which is bustling with rapid instrumental melodies. In some pieces, there are multiple melodic lines but there is no one main melody. When music is made up of equally important countermelodies, it creates a contrapuntal texture. Baroque composer J.S. Bach was one of the greatest masters of this style, such as in his Little Fugue in G minor. It starts with a single melodic line, the subject, but then a countermelody is added, and then more and more until several melodic lines are playing together. Itâs fun to listen to, but once all the countermelodies are playing together it becomes hard to decide which part to hum along with! Youâll also hear a lot of counterpoint in jazz music, in which the different instruments are all playing together and improvising their own melodies that combine to create a rich, thick musical texture. Experience the wonder of melody in music! Whether youâre humming your favorite tune, or creating a new song all your own, melody is a memorable, shareable part of music. Enrich your music experience by being aware of, listening for, and enjoying the melodies all around you.
MYTH The British helped the Jews displace the native Arab population of Palestine. FACT Herbert Samuel, a British Jew who served as the first High Commissioner of Palestine, placed restrictions on Jewish immigration âin the âinterests of the present populationâ and the âabsorptive capacityâ of the country.â1 The influx of Jewish settlers was said to force the Arab fellahin (native peasants) from their land. This was when less than a million people lived in an area that now supports more than nine million. The British limited the absorptive capacity of Palestine when, in 1921, Colonial Secretary Winston Churchill severed nearly four-fifths of Palestineâsome thirty-five thousand square milesâto create a new Arab entity, Transjordan. As a consolation prize for the Hejaz and Arabia (which are both now Saudi Arabia) going to the Saud family, Churchill rewarded Sharif Husseinâs son Abdullah for his contribution to the war against Turkey by installing him as Transjordanâs emir. The British went further and placed restrictions on Jewish land purchases in what remained of Palestine. By 1949, the British had allotted 87,500 acres of the 187,500 acres of cultivable land to Arabs and only 4,250 acres to Jews. This contradicted Article 6 of the Mandate which stated that âthe Administration of PalestineâŚshall encourage, in cooperation with the Jewish AgencyâŚclose settlement by Jews on the land, including State lands and waste lands not acquired for public purposes.â2 Ultimately, the British admitted that the argument about the countryâs absorptive capacity was specious. The Peel Commission said, âThe heavy immigration in the years 1933â36 would seem to show that the Jews have been able to enlarge the absorptive capacity of the country for Jews.â3 MYTH The British allowed Jews to flood Palestine while Arab immigration was tightly controlled. FACT The British response to Jewish immigration set a precedent of appeasing the Arabs, which was followed for the duration of the Mandate. The British restricted Jewish immigration while allowing Arabs to enter the country freely. Apparently, London did not feel that a flood of Arab immigrants would affect the countryâs âabsorptive capacity.â During World War I, the Jewish population in Palestine declined because of the war, famine, disease, and expulsion by the Turks. In 1915, approximately 83,000 Jews lived in Palestine among 590,000 Muslim and Christian Arabs. According to the 1922 census, the Jewish population was 83,000, while the Arabs numbered 643,000.4 Thus, the Arab population grew exponentially while that of the Jews stagnated. In the mid-1920s, Jewish immigration to Palestine increased primarily because of anti-Jewish economic legislation in Poland and Washingtonâs imposition of restrictive quotas.5 The record number of immigrants in 1935 (see table) was a response to the growing persecution of Jews in Nazi Germany. The British administration considered this number too large, however, so the Jewish Agency was informed that less than one-third of the quota it asked for would be approved in 1936.6 The British gave in further to Arab demands by announcing in the 1939 White Paper that an independent Arab state would be created within ten years and that Jewish immigration was to be limited to 75,000 for the next five years, after which it was to cease altogether. It also forbade land sales to Jews in 95% of the territory of Palestine. The Arabs, nevertheless, rejected the proposal. Jewish Immigration to Palestine7 1919 1,806 1931 4,075 1920 8,223 1932 12,533 1921 8,294 1933 37,337 1922 8,685 1934 45,267 1923 8,175 1935 66,472 1924 13,892 1936 29,595 1925 34,386 1937 10,629 1926 13,855 1938 14,675 1927 3,034 1939 31,195 1928 2,178 1940 10,643 1929 5,249 1941 4,592 1930 4,944 By contrast, throughout the Mandatory period, Arab immigration was unrestricted. In 1930, the Hope Simpson Commission, sent from London to investigate the 1929 Arab riots, said the British practice of ignoring the uncontrolled illegal Arab immigration from Egypt, Transjordan, and Syria had the effect of displacing the prospective Jewish immigrants.8 The British governor of the Sinai from 1922 to 1936 observed, âThis illegal immigration was not only going on from the Sinai, but also from Transjordan and Syria, and it is very difficult to make a case out for the misery of the Arabs if at the same time their compatriots from adjoining states could not be kept from going in to share that misery.â9 The Peel Commission reported in 1937 that the âshortfall of land isâŚdue less to the amount of land acquired by Jews than to the increase in the Arab population.â10 MYTH The British changed their policy to allow Holocaust survivors to settle in Palestine. FACT The gates of Palestine remained closed for the duration of the war, stranding hundreds of thousands of Jews in Europe, many of whom became victims of Hitlerâs âFinal Solution.â After the war, the British refused to allow the survivors of the Nazi nightmare to find sanctuary in Palestine. On June 6, 1946, President Truman urged the British government to relieve the suffering of the Jews confined to displaced persons camps in Europe by immediately accepting 100,000 Jewish immigrants. Britainâs foreign minister Ernest Bevin replied sarcastically that the United States wanted displaced Jews to immigrate to Palestine âbecause they did not want too many of them in New York.â11 Some Jews reached Palestine, many smuggled in on dilapidated ships organized by the Haganah. Between August 1945 and the establishment of the State of Israel in May 1948, sixty-five âillegalâ immigrant ships, carrying 69,878 people, arrived from European shores. In August 1946, however, the British began to intern those they caught in camps on Cyprus. Approximately 50,000 people were detained in the camps, and 28,000 remained imprisoned when Israel declared independence.12 MYTH As the Jewish population grew, the plight of the Palestinian Arabs worsened. FACT In July 1921, Hasan Shukri, the mayor of Haifa and president of the Muslim National Associations, sent a telegram to the British government in reaction to a delegation of Palestinians that went to London to try to stop the implementation of the Balfour Declaration. Shukri wrote: We are certain that without Jewish immigration and financial assistance there will be no future development of our country as may be judged from the fact that the towns inhabited in part by Jews such as Jerusalem, Jaffa, Haifa, and Tiberias are making steady progress while Nablus, Acre, and Nazareth where no Jews reside are steadily declining.13 The Jewish population increased by 470,000 between World War I and World War II, while the non-Jewish population rose by 588,000.14 The permanent Arab population increased by 120% between 1922 and 1947.15 This rapid growth of the Arab population was a result of several factors. One was immigration from neighboring statesâconstituting 37% of the total immigration to pre-state Israelâby Arabs who wanted to take advantage of the higher standard of living the Jews had made possible.16 The Arab population also grew because of the improved living conditions created by the Jews as they drained malarial swamps and brought improved sanitation and health care to the region. Thus, for example, the Muslim infant mortality rate fell from 201 per thousand in 1925 to 94 per thousand in 1945, and life expectancy rose from 37 years in 1926 to 49 in 1943.17 The Arab population increased the most in cities where large Jewish populations had created new economic opportunities. From 1922â1947, the non-Jewish population increased by 290% in Haifa, 131% in Jerusalem, and 158% in Jaffa. The growth in Arab towns was more modest: 42% in Nablus, 78% in Jenin, and 37% in Bethlehem.18 MYTH Jews stole Arab land. FACT Despite the growth in their population, the Arabs continued to assert they were being displaced. From the beginning of World War I, however, part of Palestineâs land was owned by absentee landlords who lived in Cairo, Damascus, and Beirut. About 80% of the Palestinian Arabs were debt-ridden peasants, semi-nomads, and Bedouins.19 Jews went out of their way to avoid purchasing land in areas where Arabs might be displaced. They sought land that was largely uncultivated, swampy, cheap, andâmost importantâwithout tenants. In 1920, Labor Zionist leader David Ben-Gurion expressed his concern about the Arab fellahin, whom he viewed as âthe most important asset of the native population.â He insisted that âunder no circumstances must we touch land belonging to fellahs or worked by them.â Instead, he advocated helping liberate them from their oppressors. âOnly if a fellah leaves his place of settlement,â Ben-Gurion added, âshould we offer to buy his land, at an appropriate price.â20 Jews only began to purchase cultivated land after buying all the uncultivated territory. Many Arabs were willing to sell because of the migration to coastal towns and because they needed money to invest in the citrus industry.21 When John Hope Simpson arrived in Palestine in May 1930, he observed, âThey [the Jews] paid high prices for the land and, in addition, they paid to certain of the occupants of those lands a considerable amount of money which they were not legally bound to pay.â22 In 1931, Lewis French conducted a survey of landlessness for the British government and offered new plots to any Arabs who had been âdispossessed.â British officials received more than 3,000 applications, of which 80% were ruled invalid by the governmentâs legal adviser because the applicants were not landless Arabs. This left only about 600 landless Arabs, 100 of whom accepted the government land offer.23 In April 1936, a new outbreak of Arab attacks on Jews was instigated by local Palestinian leaders who were later joined by Arab volunteers led by a Syrian guerrilla named Fawzi al-Qawuqji, the commander of the Arab Liberation Army. By November, when the British finally sent a new commission headed by Lord Peel to investigate, 89 Jews had been killed and more than 300 wounded.24 The Peel Commissionâs report found that Arab complaints about Jewish land acquisition were baseless. It pointed out that âmuch of the land now carrying orange groves was sand dunes or swamp and uncultivated when it was purchasedâŚThere was at the time of the earlier sales little evidence that the owners possessed either the resources or training needed to develop the land.â25 Moreover, the Commission found the shortage was âdue less to the amount of land acquired by Jews than to the increase in the Arab population.â The report concluded that the presence of Jews in Palestine, along with the work of the British administration, had resulted in higher wages, an improved standard of living, and ample employment opportunities.26 It is made quite clear to all, both by the map drawn up by the Simpson Commission and by another compiled by the Peel Commission, that the Arabs are as prodigal in selling their land as they are in useless wailing and weeping (emphasis in the original). âTransjordanâs king Abdullah27 Even at the height of the Arab revolt in 1938 (which began in April 1936 with the murder of two Jews by Arabs and the subsequent murder of two Arab workers by members of the Jewish underground28), the British high commissioner to Palestine believed the Arab landowners were complaining about sales to Jews to drive up prices for lands they wished to sell. Many Arab landowners had been so terrorized by Arab rebels they decided to leave Palestine and sell their property to the Jews.29 The Jews paid exorbitant prices to wealthy landowners for small tracts of arid land. âIn 1944, Jews paid between $1,000 and $1,100 per acre in Palestine, mostly for arid or semiarid land; in the same year, rich black soil in Iowa was selling for about $110 per acre.â30 By 1947, Jewish holdings in Palestine amounted to about 463,000 acres. Approximately 45,000 were acquired from the mandatory government, 30,000 were bought from various churches, and 387,500 were purchased from Arabs. Analyses of land purchases from 1880 to 1948 show that 73% of Jewish plots were purchased from large landowners, not poor fellahin.31 Many leaders of the Arab nationalist movement, including members of the Muslim Supreme Council, and the mayors of Gaza, Jerusalem, and s sold land to the Jews. Asâad el-Shuqeiri, a Muslim religious scholar and father of Palestine Liberation Organization chairman Ahmed Shuqeiri, took Jewish money for his land. Even King Abdullah leased land to the Jews.32 MYTH The British helped the Palestinians to live peacefully with the Jews. FACT In 1921, Haj Amin el-Husseini first began to organize fedayeen (âone who sacrifices himselfâ) to terrorize Jews. El-Husseini hoped to duplicate the success of Kemal AtatĂźrk in Turkey by driving the Jews out of Palestine just as Kemal had driven the invading Greeks from his country.33 Arab radicals gained influence because the British administration was unwilling to take effective action against them until they began a revolt against British rule. Colonel Richard Meinertzhagen, former head of British military intelligence in Cairo, and later chief political officer for Palestine and Syria, wrote in his diary that British officials âincline towards the exclusion of Zionism in Palestine.â The British encouraged the Palestinians to attack the Jews. According to Meinertzhagen, Col. Bertie Harry Waters-Taylor (financial adviser to the military administration in Palestine 1919â23) met with el-Husseini in 1920, a few days before Easter, and told him that âhe had a great opportunity at Easter to show the worldâŚthat Zionism was unpopular not only with the Palestine administration but in Whitehall.â He added that âif disturbances of sufficient violence occurred in Jerusalem at Easter, both General [Louis] Bols [chief administrator in Palestine, 1919â20] and General [Edmund] Allenby [commander of the Egyptian force, 1917â19, then high commissioner of Egypt] would advocate the abandonment of the Jewish Home. Waters-Taylor explained that freedom could only be attained through violence.â34 El-Husseini took the colonelâs advice and instigated a riot. The British withdrew their troops and the Jewish police from Jerusalem, allowing the Arab mob to attack Jews and loot their shops. Because of el-Husseiniâs overt role in instigating the pogrom, the British decided to arrest him. He escaped, however, and was sentenced to ten years in absentia. A year later, some British Arabists convinced High Commissioner Herbert Samuel to pardon el-Husseini and to appoint him Mufti (a cleric in charge of Jerusalemâs Islamic holy places). By contrast, Vladimir Jabotinsky and several followers, who had formed a Jewish defense organization during the unrest, were sentenced to 15 years. They were released a few months later.35 Samuel met with el-Husseini on April 11, 1921, and was assured âthat the influences of his family and himself would be devoted to tranquility.â Three weeks later, riots in Jaffa and elsewhere left forty-three Jews dead.36 El-Husseini consolidated his power and took control of all Muslim religious funds in Palestine. He used his authority to gain control over the mosques, the schools, and the courts. No Arab could reach an influential position without being loyal to the Mufti. His power was so absolute that âno Muslim in Palestine could be born or die without being beholden to Haj Amin.â37 The Muftiâs henchmen also ensured he would have no opposition by systematically killing Palestinians who discussed cooperation with the Jews from rival clans. As the spokesman for Palestinian Arabs, el-Husseini did not ask that Britain grant them independence. On the contrary, in a letter to Churchill in 1921, he demanded that Palestine be reunited with Syria and Transjordan.38 The Arabs found rioting an effective political tool because of the lax British response toward violence against Jews. In handling each riot, the British prevented Jews from protecting themselves but made little effort to prevent the Arabs from attacking them. After each outbreak, a British commission of inquiry would try to establish the cause of the violence. The conclusion was always the same: The Arabs feared being displaced by the Jews. To stop the rioting, the commissions would recommend that restrictions be placed on Jewish immigration. Thus, the Arabs learned they could always stop the influx of Jews by staging riots. This cycle began after a series of riots in May 1921. After failing to protect the Jewish community from Arab mobs, the British appointed the Haycraft Commission to investigate the cause of the violence. Although the panel concluded the Arabs had been the aggressors, it rationalized the cause of the attack: âThe fundamental cause of the riots was a feeling among the Arabs of discontent with, and hostility to, the Jews, due to political and economic causes, and connected with Jewish immigration, and with their conception of Zionist policy.â39 One consequence of the violence was the institution of a temporary ban on Jewish immigration. The Arab fear of being âdisplacedâ or âdominatedâ was an excuse for their attacks on Jewish settlers. Note, too, that these riots were not inspired by nationalistic fervorânationalists would have rebelled against their British overlordsâthey were motivated by economics, the radical Islamic views of the Mufti, and misunderstanding. In 1929, Arab provocateurs convinced the masses that the Jews had designs on the Temple Mount (a tactic still used today to incite violence). A Jewish religious observance at the Western Wall, which forms a part of the Temple Mount, served as a pretext for rioting by Arabs against Jews, which spilled out of Jerusalem into other villages and towns, including Safed and Hebron. Again, the British administration made no effort to prevent the violence, and, after it began, the British did nothing to protect the Jewish population. After six days of mayhem, the British finally brought troops in to quell the disturbance. By this time, most of Hebronâs Jews had fled or been killed. In all, 133 Jews were killed and 399 wounded in the pogroms.40 After the riots, the British ordered an investigation, resulting in the Passfield White Paper. It said the âimmigration, land purchase and settlement policies of the Zionist Organization were already or were likely to become, prejudicial to Arab interests. It understood the mandatory governmentâs obligation to the non-Jewish community to mean that Palestineâs resources must be primarily reserved for the growing Arab economy.â41 This meant it was necessary to restrict Jewish immigration and land purchases. MYTH The Mufti was not a Nazi collaborator. FACT In 1941, Haj Amin al-Husseini, the Mufti of Jerusalem, fled to Germany and met with Adolf Hitler, Heinrich Himmler, Joachim Von Ribbentrop, and other Nazi leaders. He wanted to persuade them to extend the Nazisâ anti-Jewish program to the Arab world. The Mufti sent Hitler fifteen drafts of declarations he wanted Germany and Italy to make concerning the Middle East. One called on the two countries to declare the illegality of the Jewish home in Palestine. He also asked the Axis powers to âaccord to Palestine and to other Arab countries the right to solve the problem of the Jewish elements in Palestine and other Arab countries in accordance with the interest of the Arabs, and by the same method that the question is now being settled in the Axis countries.â42 In November 1941, the Mufti met with Hitler, who told him the Jews were his foremost enemy. The Nazi dictator rebuffed the Muftiâs requests for a declaration in support of the Arabs, however, telling him the time was not right. The Mufti offered Hitler his âthanks for the sympathy which he had always shown for the Arab and especially Palestinian cause, and to which he had given clear expression in his public speeches.â He added, âThe Arabs were Germanyâs natural friends because they had the same enemies as had Germany, namelyâŚthe Jews.â Hitler told the Mufti he opposed the creation of a Jewish state and that Germanyâs objective was destroying the Jewish element in the Arab sphere.43 In 1945, Yugoslavia sought to indict the Mufti as a war criminal for his role in recruiting twenty thousand Muslim volunteers for the SS, who participated in the killing of Jews in Croatia and Hungary. He escaped French detention in 1946, however, and continued his fight against the Jews from Cairo and later Beirut where he died in 1974. MYTH The bombing of the King David Hotel was part of a deliberate terror campaign against civilians. FACT British troops seized the Jewish Agency compound on June 29, 1946, and confiscated large quantities of documents. At about the same time, more than 2,500 Jews from all over Palestine were arrested. A week later, news of a massacre of 40 Jews in a pogrom in Poland reminded the Jews of Palestine how Britainâs restrictive immigration policy had condemned thousands to death. In response to the British provocations, and a desire to demonstrate that the Jewsâ spirit could not be broken, the United Resistance Movement planned to bomb the King David Hotel, which housed the British military command and the Criminal Investigation Division in addition to hotel guests. The Haganah pulled out of the plot and left it up to the Irgun. Irgun leader Menachem Begin stressed his desire to avoid civilian casualties and the plan was to warn the British so they would evacuate the building before it was blown up. Three telephone calls were placed on July 22, 1946, one to the hotel, another to the French Consulate, and a third to the Palestine Post warning that explosives in the King David Hotel would soon be detonated. The call to the hotel was received and ignored. Begin quotes one British official who supposedly refused to evacuate the building, saying, âWe donât take orders from the Jews.â44 As a result, when the bombs exploded, the casualty toll was high: 91 killed and 45 injured. Among the casualties were 15 Jews. Few people in the main part of the hotel were injured.45 For decades, the British denied they had been warned. In 1979, however, a member of the British Parliament provided the testimony of a British officer who heard other officers in the King David Hotel bar joking about a Zionist threat to the headquarters. The officer who overheard the conversation immediately left the hotel and survived.46 In contrast to Arab attacks against Jews, which Arab leaders hailed as heroic actions, the Jewish National Council denounced the bombing of the King David.47 1 Aharon Cohen, Israel and the Arab World, (NY: Funk and Wagnalls, 1970), p. 172
Organic Nomenclature. What are aliphatic compounds or aliphatic hydrocarbons? An aliphatic compound or aliphatic hydrocarbon is an organic compound containing hydrogen and carbon atoms that are usually linked together in chains that are straight. The term Aliphatic has been derived from the Greek word âAleipharâ which translates to âfatâ. It is used to describe hydrocarbons that are obtained by the chemical degradation of oils or fats. What are aliphatic compounds or aliphatic hydrocarbons? The simplest organic compounds are those composed of only two elements: carbon and hydrogen. These compounds are called hydrocarbons. Hydrocarbons are separated into two types: aliphatic hydrocarbons and aromatic hydrocarbons. Aliphatic hydrocarbons are hydrocarbons based on chains of C atoms. There are three types of aliphatic hydrocarbons: Alkanes are aliphatic hydrocarbons with only single covalent bonds. Alkenes are hydrocarbons that contain at least one CâC double bond, and alkynes are hydrocarbons that contain a CâC triple bond. Occasionally, we find an aliphatic hydrocarbon with a ring of C atoms; these hydrocarbons are called cycloalkanes (or cycloalkenes or cycloalkynes). The simplest alkanes have their C atoms bonded in a straight chain; these are called normal alkanes. They are named according to the number of C atoms in the chain. The smallest alkane is methane: molecule is three dimensional, with the H atoms in the positions of the four corners of a tetrahedron. The diagrams representing alkanes are called structural formulas because they show the structure of the molecule. As molecules get larger, structural formulas become more and more complex. One way around this is to use a condensed structural formula, which lists the formula of each C atom in the backbone of the Molecule. The condensed formulas show hydrogen atoms right next to the carbon atoms to which they are attached, as illustrated for butane: The ultimate condensed formula is a line-angle formula (or line drawing) , in which carbon atoms are implied at the corners and ends of lines, and each carbon atom is understood to be attached to enough hydrogen atoms to give each carbon atom four bonds. For example, we can represent pentane (CH3CH2CH2CH2CH3) and isopentane [(CH3)2CHCH2CH3] as follows: Unsaturated Hydocarbons: Alkenes and Alkynes Alkenes Organic compounds that contain one or more double or triple bonds between carbon atoms are described as unsaturated. Unsaturated hydrocarbons have less than the maximum number of H atoms possible. Unsaturated hydrocarbon molecules that contain one or more double bonds are called alkenes. Carbon atoms linked by a double bond are bound together by two bonds, one Ď bond and one Ď bond. Double and triple bonds give rise to a different geometry around the carbon atom that participates in them, leading to important differences in molecular shape and properties. The differing geometries are responsible for the different properties of unsaturated versus saturated fats. Naming Alkenes and Alkynes Alkenes and alkynes are named in a similar fashion. The biggest difference is that when identifying the longest carbon chain, it must contain the CâC double or triple bond. Furthermore, when numbering the main chain, the double or triple bond gets the lowest possible number. This means that there may be longer or higher-numbered substituents than may be allowed if the molecule were an alkane. For example, this molecule is 2,4-dimethyl-3-heptene (note the number and the hyphens that indicate the position of the double bond). â Unsaturated Hydocarbons: Alkenes and Alkynes Unsaturated Hydocarbons: Alkenes and Alkynes Alkynes Hydrocarbon molecules with one or more triple bonds are called alkynes; they make up another series of unsaturated hydrocarbons. Two carbon atoms joined by a triple bond are bound together by one Ď bond and two Ď bonds. The sp-hybridized carbons involved in the triple bond have bond angles of 180°, giving these types of bonds a linear, rod-like shape. The simplest member of the alkyne series is ethyne, C2H2, commonly called acetylene. The Lewis structure for ethyne, a linear molecule, is: Properties of Unsaturated Hydocarbons: Alkenes and Alkynes Ethylene (the common industrial name for ethene) is a basic raw material in the production of polyethylene and other important compounds. Over 135 million tons of ethylene were produced worldwide in 2010 for use in the polymer, petrochemical, and plastic industries. Ethylene is produced industrially in a process called cracking, in which the long hydrocarbon chains in a petroleum mixture are broken into smaller molecules. Halogens can also react with alkenes and alkynes, but the reaction is different. In these cases, the halogen reacts with the CâC double or triple bond and inserts itself onto each C atom involved in the multiple bonds. This reaction is called an addition reaction. One example is Properties of Unsaturated Hydocarbons: Alkenes and Alkynes Hydrogen can also be added across a multiple bond; this reaction is called a hydrogenation reaction. In this case, however, the reaction conditions may not be mild; high pressures of H2 gas may be necessary. A platinum or palladium catalyst is usually employed to get the reaction to proceed at a reasonable pace: CH2=CH2+H2âmetalcatalystCH3CH3 CH2=CH2+H2âmetalcatalystCH3CH3.