There is a metal ball and ring set that is specially made so that at room temperature the ball fits through the ring. However, when the ball is heated, it gets stuck and cannot fit through anymore.  When heated, the ball gets a little bigger!

Which of the following explains the arrangement and motion of atoms in the metal ball as it gets slightly larger during heating?

To make bread dough, a cook mixes flour, water, salt and yeast. After mixing, the dough is placed in a container for several hours to allow the process offer mentation to take place. During fermentation, a chemical change occurs in the dough: the yeast (a single-celled fungus) helps to transform the starch and sugars in the flour into carbon dioxide and alcohol.

Fermentation causes the dough to rise. Why does the dough rise? (Choose 3 answers)

When metals react with other substances, the gradual wearing away or corrosion of a metal results. Corrosion is the reaction of metal with oxygen to form oxides or rust. This may lead to deterioration of metals. The higher the metal's reactivity, the more likely it is to rust. Corrosion or rusting is destructive to iron (Fe) which is the widely used metal due to its abundance.

The following are ways to prevent corrosion of metals:

1. Coating metal with organic materials such as paint, lacquer, grease, or asphalt.

2. Coating with ceramic enamel, like that used in sinks, bathtubs, stoves, refrigerators and washers.

3. Coating with adherent oxide, which is formed by exposing iron to superheated steam, giving it an adherent coating of Fe₃O₄

4. Mixing metals such as: stainless steel (Fe, Cr and Cu) or duriron (Fe and Si).

5. Coating (by electroplating) with another metal such as zinc (galvanizing), copper, nickel, chromium or tin

Metals vary in reactivity. The most reactive metals will react even with cold water while the least will not react even with acid. There is an existing definite order of reactivity existing among metals and hydrogen according to their ability to displace one another. This arrangement is called the metal reactivity series or activity series of metal. The activity series is an arrangement of metals according to decreasing order of reactivity as shown in table. The metals that are higher in position than hydrogen in the activity series is more reactive. A metal more reactive than hydrogen can displace hydrogen during a chemical reaction producing hydrogen gas. Those that are below hydrogen in the activity series are less reactive which means they cannot displace hydrogen during chemical reaction. Hydrogen is found in all acids.

Based on the experiment result of Karen and David, arrange the metals according to increasing reactivities.

"You are observing the motion of a car during a test drive. The car starts from rest at a traffic signal. Over the first 5 seconds, the driver gradually increases the speed by pressing the accelerator pedal uniformly. Once the car reaches a steady cruising speed, the driver maintains that constant velocity for the next 10seconds." 

What does the horizontal line on the velocity-time graph from 5 to 15 seconds represent about the car's motion?(Select three correct answers)

A bus is driving along a straight stretch of road. The bus driver, named Ray, has a cup of water resting on the dashboard: Suddenly Ray has to slam on the brakes. 

What is most likely to happen to the water in the cup?

The electromagnetic spectrum is a range of frequencies, wavelengths and photon energies covering frequencies from below 1 hertz to above 1025 Hz, corresponding to wavelengths which are a few kilometers to a fraction of the size of an atomic nucleus in the spectrum of electromagnetic waves as shown in diagram below.

Use the model to rank the following bands of the EM spectrum by frequency with 1 being the highest frequency and 4 being with the least.

Block A starts with initial speed [Vo] and slides down a friction less incline of height [h]. Block B is thrown horizontally with speed [Vo] from height [h]. The blocks are identical.

Which block hits the ground with the greatest speed?

Choose1 answer. 

A cyclist is riding up a hill at a constant speed. Which of the following statements explains why the cyclist is not accelerating?

Two small spheres are charged with opposite types of charge and placed a certain distance apart. If the charge on one sphere is doubled, what happens to the electrostatic force between the spheres?

Bacteria that live in our mouths cause dental caries (tooth decay). Caries have been a problem since the 1700s when sugar became available from the expanding sugarcane industry.

Today, we know a lot about caries. For example:

·      Bacteria that cause caries feed on sugar.

·      The sugar is transformed to acid.

·      Acid damages the surface of teeth.

·      Brushing teeth will prevent caries.

What is the role of bacteria in dental caries?

The following graph shows the consumption of sugar and the amount of caries in different countries. 

Each country is represented by a dot in the graph.

Which one of the following statements is supported by the data given in the graph?

The figures below illustrate a mutation in an organism’s gene sequence. Figure 1 shows the normal nucleotide sequence of a gene while figure 2 shows the mutated version of the same gene.

Which of this best predicts the effect of the mutation on the organism?  The effect of the mutation will be_______.

Read the following passage to answer the question that follows:

Which two statements describe the most likely results of the gene mutation.  

I. The person’s health will be negatively affected.

II. The person’s PAH protein will not function normally.

III. The person’s blood will contain a normal level of phenylalanine.

IV. The person’s PAH protein will have a different structure, but this will not affect the protein’s function.

Compare the processes in the illustration and check the box/es of the correct answer/s.

Major surgery, performed in specially equipped operating theatres, is necessary to treat many diseases.

While undergoing major surgery, patients are anesthetized so they don’t feel any pain. The anesthetic is often administered as agas through a face mask that covers the nose and mouth.

Are the following human systems involved in the action of anesthetic gases in the human body? 

The graph shows the cumulative percentage of vertebrate species extinctions over time, broken down by different groups (mammals, birds, reptiles, fish, and amphibians). Concern is rising that mass extinctions of many species may increase. In the graph below, the risk of extinctions is shown to have risen rapidly from 1850 to 2014.

Match each vertebrate group with the trend that best describes its extinction pattern from 1500 to 2014, as shown in the graph.

Read the following newspaper article and answer the questions which follow.

In lines 9 and 10 it is stated that “Food web A represents a more diverse ecosystem with, as a result, many more alternative feeding pathways.”

Look at FOOD WEB A. Only two animals in this food web have three direct (immediate) food sources.

Which two animals are they?

Food webs A and B are in different locations. Imagine if Leaf Hoppers died out in both locations. Which one of these is the best prediction and explanation for the effect this would have on the food webs?

The diagrams below show the number of fish in a lake and the average water temperature in the lake for the months of May through October. During certain times of the year, bears feed heavily on a population of fish in a lake. At other times of the year, the bear population feeds primarily on fruits, berries, and insects.

During which month would the bears in the area have the most fish available?

Mercury Levels in Various Fish or Seafood Types Industrialization has contributed to unsafe levels of mercury compounds building up in aquatic ecosystems, including in the tissues of many predatory fish species. As a result, many people have concerns about eating seafood. The mercury, at relatively high levels, can be especially harmful during development of a fetus and of young children. It can also affect adult health in various ways. However, seafood is also an important part of a healthy diet. The omega-3 fats in seafood are essential to the proper functioning of the circulatory system. They are also important for optimal development of a baby’s brain and nervous system. The table below contains data about mercury levels in several kinds of seafood.

Based on the information given, which statement concerning the eating of fish and seafood is most accurate?

Mercury Levels in Various Fish or Seafood Types Industrialization has contributed to unsafe levels of mercury compounds building up in aquatic ecosystems, including in the tissues of many predatory fish species. As a result, many people have concerns about eating seafood. The mercury, at relatively high levels, can be especially harmful during development of a fetus and of young children. It can also affect adult health in various ways. However, seafood is also an important part of a healthy diet. The omega-3 fats in seafood are essential to the proper functioning of the circulatory system. They are also important for optimal development of a baby’s brain and nervous system. The table below contains data about mercury levels in several kinds of seafood.

Match each seafood-related concept to the appropriate description or impact based on the information provided.

The photograph below shows the effect of wildfire in California now.

The photograph below shows the result of a deadly wildfire in California in 2018. The same wildfire is happening now.

What is most likely expected to occur to thisecosystem in the future?

Triangulation is a method that uses distance information determined from three seismic stations to locate the epicenter of an earthquake.  On the map of active faults in the Visayas and Mindanao, circles are drawn around these seismic stations.  The circle represents the calculated distance of the earthquake from the station.   The location where all the circles intersect is the earthquake epicenter.

A hypothetical tectonic earthquake hits theVisayas and Mindanao as shown in the records from three earthquake stations.  Which fault line could have generated the earthquake? 

The figure below is Plate Tectonic Map.  The point of the arrows shows the direction the lithospheric plates are moving. 

Look at the different points labeled A-E in the map.  Grouped the statements if Yes or No, if the geologic events and structures occur at these points.

EVOLUTION

Most horses today are streamlined and can run fast.

Scientists have found the fossil skeletons of animals that are similar to horses. They consider them to be the ancestors of the present-day horse. The scientists have also been able to determine the period during which the fossil species were living.

What further research can scientists undertake to find out how horses have evolved over time?

Link “Yes” or “No” for each of these statements.

EVOLUTION

Most horses today are streamlined and can run fast.

Scientists have found the fossil skeletons of animals that are similar to horses. They consider them to be the ancestors of the present-day horse. The scientists have also been able to determine the period during which the fossil species were living.

Which one of the following statements best applies to the scientific theory of evolution?

On 8 June 2004, the planet Venus could be seen passing in front of the Sun when viewed from many places on Earth. This is called a “transit” of Venus and happens when its orbit takes Venus between the Sun and Earth. The previous transit of Venus occurred in 1882 and another is predicted to occur in 2012. Below is a picture of the transit of Venus in 2004. A telescope was pointed at the Sun and the image projected onto a white card.

Why was the transitobserved by projecting the image onto a white card, rather than by lookingdirectly

Many people believe that wind should replace oil and coal as a source of energy for producing electricity. The structures in the picture are windmills with blades that are rotated by the wind. These rotations cause electricity to be produced by generators that are turned by the windmills.

The graphs below show the average windspeeds in four different places throughout a year. Which one of the graphs indicates the most appropriate place to establish a wind farm for generating electricity? 

The higher the altitude the more slowly windmills rotate at the same wind speed.

Which one of the following is the best reason why the blades of windmills rotate more slowly in higher places at the same wind speed?

The Big Bang is a physical theory that describes how the universe expanded from an initial state of high density and temperature. The notion of an expanding universe was first scientifically originated by physicist Alexander Friedmann in 1922 with the mathematical derivation of the Friedmann equations.

According to the Big Bang theory, which graph best represents the relationship between time and the size of the universe from the beginning of the universe to the present?

The figure below shows how water supplied to houses in cities is made fit for drinking.

The cleaning of water often happens in several steps, involving different techniques. The cleaning process shown in the figure involves four steps (numbered 1–4). In the second step, the water is collected in a settling pond.

In what way does this step make the water cleaner?

Can drinking polluted water cause the following health problems? Linked the statements if “Yes” or “No” in each case. 

Can drinking polluted water cause this health problem? Yes or No?

Globally, both population and resource extraction increased by almost50% in the 25 years from 1980 to 2005 (SERI et al., 2009). Over that time, the world population increased from 4.44 billion in 1980 to 6.49 billion.

The figure below shows how the extraction of natural resources increased between 1980 and 2005 from 40 billion tons to 58 billion tons. The graph shows the extraction of four types of natural resource: fossil fuels, biomass, metal sand minerals. Biomass means biological material derived from living organisms such as crops, livestock, fish, wood, etc. Metals are used in the manufacture of a wide range of goods – from cars to computers. Minerals are used in industrial processes and in construction to build our houses and roads. Both metals and minerals are obtained from rocks that have been mined and are then processed in various ways to extract valuable resources.

Identify and group each statement as true or false from the information given. 

Globally, both population and resource extraction increased by almost50% in the 25 years from 1980 to 2005 (SERI et al., 2009). Over that time, the world population increased from 4.44 billion in 1980 to 6.49 billion.

The figure below shows how the extraction of natural resources increased between 1980 and 2005 from 40 billion tons to 58 billion tons. The graph shows the extraction of four types of natural resource: fossil fuels, biomass, metal sand minerals. Biomass means biological material derived from living organisms such as crops, livestock, fish, wood, etc. Metals are used in the manufacture of a wide range of goods – from cars to computers. Minerals are used in industrial processes and in construction to build our houses and roads. Both metals and minerals are obtained from rocks that have been mined and are then processed in various ways to extract valuable resources.

Which of the following is a significant environmental impact of mining?

Which organism probably exists the longest time in that place based on the outcrops?