Examples of Organic Fertilizer

Classification of plants • Plants can be classified as cultivated and wild plants. • Both cultivated and wild plants are very useful to people, animals and the environment. 1. Cultivated plants: • Cultivated plants are plants grown by people for selling. • They can be grown in the field, vegetable garden, home garden and orchard. Classification of plants 2. Wild plants Wild plants are plants that grow on their own outside the garden, orchard or field. They have many uses such as: • Food for people and animals • Shelter • Source of fuel in form of firewood. • Examples include, grasses, msasa, yellow wood, mahogany, mopane Plant Nutrition • The presence of plant nutrients in the soil make them grow well. • The three major plant nutrients are nitrogen, phosphorus and potassium. Sources of plant nutrients • The source for plant nutrients are grouped into organic and inorganic sources. Organic sources of plant nutrients • These are found in nature. • They are natural materials such, decayed plant and animal matter which include: • Animal manure from cattle, sheep, goats, poultry and pigs. • Green manure • Legume crops like beans, peas and groundnuts. • Humus • These material sources may also be called natural fertilizers. Inorganic sources of plant nutrients • These are sources of plant nutrients made by people in industries. They include: • Compound fertilizers like compound A, B, C and D. • These have two or more nutrients. • Straight fertilizers like ammonium nitrate, single super phosphate and urea. • A straight fertilizer supplies a single or more nutrient to the crop. A straight fertilizer A Compound fertilizer Sources of N,P,K • Ammonium nitrate and Urea- contain nitrogen Double super Phosphate, Single super phosphate-contain phosphorus • Muriate of Potash contains Potassium 2 . Compound fertilisers -have two or three of the three major plant nutrients (N.P.K). N-nitrogen P-phosphorus K-potassium Examples Compound D Wednesday 17 May 2023 Revision exercise (Plant nutrition) 1 .Name the 3 plant nutrients needed by plants. 2. What are the 2 groups of plant nutrients sources? 3. Give 3 examples of organic sources of plant nutrients. 4. What is a straight fertilizer? 5. Compound fertilizer supplies ……………or ………………. Nutrients. Vegetable crops • A vegetable is any part of a plant that is eaten by humans as food part of a meal. • Vegetables are grouped and named according to the part that is eaten. • These are leaf, root, fruit, flower, bulb, tuber and legume vegetables. Leaf vegetables Types of veg Legume etable cropsvegetables Fruit vegetables Root, bulb and tuber Flower vegetables Cabbage Peas Tomato Root: carrots Cauliflower Rape Green beans Pepper Parsnip broccoli Spinach Melons Beetroot Tsunga Cucumber Bulb: onion Lettuce Squash Garlic kale Egg plant Leek chillies Tuber: Irish potato Wednesday 31 May 2023 Vegetable crops 1. What is a vegetable? 2. Which one is not a vegetable from the list below? a. Covo B. cabbage C. wheat D. tomato 3. Choose a vegetable which is not a fruit vegetable. a. tomato B. pepper C. kale D. egg plant 4. From which pair of vegetables do we eat the flower? A. cauliflower and garlic B. broccoli and cauliflower C. broccoli and rape D. cauliflower and pepper 5. Give one example of a vegetable belonging to each of the following groups. a. root b. legume c. bulb 6. Name any 5 groups of vegetable classification according to the parts eaten. Growing leaf vegetables • Although there are many types of vegetables, the leaf, fruit and bulb vegetables are widely grown. • Leaf vegetables form the greater part of vegetable crops. • Leaf vegetables belong to a family called brassica. • Brassicas include cabbages, lettuce, spinach, covo and many others. • Each brassica family has got its own varieties called cultivar. • They usually grow under the same climatic conditions and are affected by the same pests and diseases. • The selection of a variety depends on the following : The intended use of the vegetable, for example, salad, stew or snacks. Days taken to mature. Disease resistant Season of the year Seedbed preparation • Brassica vegetables are usually raised in seedbeds. • The seedbeds are prepared by: • Marking the position of the bed 1 meter in width by any length using a tape measure, hammer and pegs. • Digging a seedbed to a depth of 25 to 30cm using a hoe. • Breaking lumps of soil using a garden rake. Soil requirements • Brassicas need: • Well drained soils. • Fertile soil for good growth • Slightly acidic soils (pH 5.5-6) Climatic requirements • Brassicas need cool to warm temperatures. • Very low temperatures cause cabbages to flower which is called bolting. • Brassicas can be grown throughout the year. Seedbed preparation • Brassica seedlings are usually raised in seedbeds. • A seedbed is prepared by: Marking the position of the bed 1 metre in width by any length using a tape measure, hammer and pegs. Digging a seedbed to depth of 25 to 30 cm using a hoe. Breaking lumps of soil using a garden rake. This is done in order to have a fine tilth and improve soil to seed contact. Making ridges that a 15cm high. Apply 3 to 5kg/m² of well decomposed manure. 60 to 100g/m² of compound fertilizer can be added into the soil. Management of vegetable crops • After transplanting the seedlings, the seedlings need to be looked after. (a)Controlling weeds: all vegetables must be kept weed free. • This is done either by hand pulling weeds or shallow cultivation using a hand fork. (b) Pest control: common pests that affect the brassicas are aphids and diamond black moth larva. • Aphids are small green insects that suck the juice from the leaves leaving them with curls. • They are controlled by spraying malathion using the instructions on the label. (c) Disease control: bacterial diseases are common in brassicas. • Common diseases are black rot and soft rot, especially in cabbages. • These are controlled by: Crop rotation Early planting Planting resistant cultivars (d) Top dressing: brassicas are top dressed using Ammonium Nitrate at a rate of 2.5g per plant. • Top dressing is usually done 3 or 4 weeks after germination. FIELD CROPS • Field crops are crops that are grown on a large piece of land. • Example of field crops:  Maize  Cotton  Groundnuts  Roundnuts  Wheat  Sunflower  Tobacco  Sugar cane  Tea  Coffee  Soya beans  sorghum Classification of field • Field crops can be classified according to use such crops cereal, fibre, sugar and oil. 1. Cereal crops: • A cereal is a grass grown for its edible seeds. • They are also known as grain crops. • The major cereal crops are maize, wheat, rice, barley, sorghum and millet. 2 . fiber crops : • these are crops which are grown for their fiber and are used in making textiles, ropes and rugs. • Important fiber crops are cotton, flax and sisal 3. Oil seed crops: • These crops are grown for the purpose of extracting oil from their seed. • The main oil seed crops are groundnuts, sunflower, soyabean and cotton seed. 4 . Sugar crops : • Sugar crops include sugarcane,

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 (“two atoms”) molecules H2, N2, O2, F2, Cl2, Br2, and I2 (part (a) in Figure 3.1.1). Similarly, a few pure elements exist as polyatomic (“many atoms”) 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 13–15, 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 “laughing gas,” 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 “unpressurized” 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 O2−. 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 NO3− ions combine in a 1:1 ratio to form KNO3 (potassium nitrate or saltpeter), a major ingredient in black gunpowder. Similarly, Ca2+ and SO42− form CaSO4 (calcium sulfate), which combines with varying amounts of water to form gypsum and plaster of Paris. The polyatomic ions NH4+ and NO3− 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 PO43− 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(−3) = −6], 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 PO43− 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.

1 .Sand soil • Has course/ large particles • they are larger than those of clay • Loses water quickly • Has less organic matter • Has good aeration • Allows good root penetration • Leaching of nutrients is more in sand soil. • Does not stick when wet 2. Clay soil • Has very fine particles which are closely packed • The soil is sticky when wet and can be moulded into any shape • It holds more water than sand and loam • It has poor drainage • It cracks when dry • It has poor aeration • It does not allow good root penetration 2 .Loam soil • Is a mixture of sand and clay particles • It half clay half sand • It can be easily moulded into a shape but easily crumbles • Holds water for a longer time than sand • It sticks on the hands when wet • It has good drainage • It has good aeration • It allows good root penetration • Loam is the best soil Soil Fertility • When soil has enough plant nutrients it is fertile • Soil fertility is the presence of nutrients in the soil • A farmer can add nutrients to the soil to make it fertile • This is done by applying fertilizers and compost. • A fertiliser is a substance that is added to the soil to increase fertility • Nutrients found in the soil include Nitrogen, Phosphorus and Potassium ( NPK ) • They are called major nutrients or macro nutrients because they are needed in large quantities Minor nutrients • Minor nutrients are needed in smaller quantities • Minor nutrients are also called micro nutrients or trace elements • Examples of minor nutrients are boron, iron, zinc, manganese, magnesium and molybdenum Soil erosion • Is the washing away of top soil by agents such as Water Wind Animals Humans 1. Water: • Water washes away soil when it rains. • Loose soil is washed away into dams and rivers. • Steep slopes also lead to soil erosion. • Ploughing 2 . Wind • The blowing away of soil by wind causes soil erosion. • When people cut down trees wind erosion easily takes place. • Type of soil also leads to wind erosion. Which soil type is easily eroded by wind? 3 . Animals • Animal cause soil erosion by overgrazing. • Overgrazing is when animals eat plant or vegetation leaving the ground surface bare. • Animals walking on the same pathway for a long time make the soil loose. • Animals that live underground also burrow loosening the soil. • This makes soil break easily and get washed away. WATER WATER CONSERVATION Water • Water is important in agriculture • It is used to: Clean farm tools Mould bricks Wash milking equipment Cool machines Provide homes(habitat) for fish Give animals drinking and bathing water Sources of Water Natural sources 1. Natural rains: • rain water from the clouds is a primary source of water. • It is used to water crops such as maize, millet, sorghum and so on during the rainy season. • Rain water that collects into the rivers and dams is used by animals and people for drinking. 2 . Rivers : • Rivers are some of the major sources of water for different activities such as fishing, boat cruising and irrigation. 3 . Streams : • A stream is a small river. • Streams supply water for irrigating garden crops especially in rural areas. • They are also a source of water for animals to drink and bath. Sources of Water 4 . Springs : • Springs are usually found on hilly areas. • They result from pressure of underground streams. • The pressure forces water underground to form a channel to the surface of the soil and flow above the ground. Sources of Water Man made sources Man discovered that water for agriculture was not enough during the rain and cool dry seasons. They decided to make structures which would harvest or collect and store water for future use. 1.Protected well: • Wells are dug in the ground by hand. • They are often lined with bricks and concrete so that they do not cave in. • Protected wells are covered, therefore are safe to drink from. 2 . borehole : • They are deep holes made by drilling machines. • Drilling can be done up to 70 metres deep. • Water is pumped using an electric pump or hand pump. Sources of Water 3 . Dams : • A dam is a large wall or barrier built to hold water to save it for future use. 4 . Weir : • A weir is made by construction a cement brick wall or concrete wall across a river to trap water and eroded soil. • water flows over the wall when the river is inflood. 5 .Water tank : • Is a temporary manmade water source. • Water from a water tank is usually harvested from roof tops or it works along a borehole or protected well as temporary storage. • Water is pumped from the borehole or protected well into the water tank. 6 . reservoir : • A large natural or manmade lake used as a source of water. PLANTS Uses of plants • Fibre for making clothes • Oil for cooking, making paint and chemicals • Sugar for tea • Wood for timber • Refreshing drinks and alcohol • Food for people and animals • Protect the soil from erosion • Plants supply us with fresh oxygen for breathing. • Some plant parts are used as medicine.

Meaning Of Refuse Refuse are dirty substances or unwanted wastes we have used at home and are ready to be disposed. Refuse should not be kept within the home for a long time to avoid breeding space for pests and bacteria which could bring various infections and dangerous diseases. We can clear refuse by sweeping our surroundings and gathering used items such as can, food remnants, leaves, banana peel, etc. in other to avoid infections and dangerous diseases. The following are the materials used to gather refuse. 1. Brooms 2. Packers 3. Waste basket 4. Dust bins 5. Incinerators Types of Wastes 1) Organic Wastes: These are perishables wastes. They can decay easily. Examples are Yam peels, banana peels, fish wastes etc. These wastes could be burnt when dried . 2) Solid Wastes: These are non-perishable wastes. It takes a long process before these wastes can decay. Examples are cans, tins, broken glasses and bottles. These wastes can be buried. It can also be re-cycled for new things. The following are ways of disposing refuse. 1) Gather the refuse at safe distance and burn them. 2) Bury the refuse by digging hole and pouring them. 3) By recycling refuse to become fertilizer for gardening or farming.

Ions Ions are charged substances that have formed through the gain or loss of electrons. Cations form from the loss of electrons and have a positive charge while anions form through the gain of electrons and have a negative charge. Cation Formation Cations are the positive ions formed by the loss of one or more electrons. The most commonly formed cations of the representative elements are those that involve the loss of all of the valence electrons. Consider the alkali metal sodium (Na) . It has one valence electron in the n=3 energy level. Upon losing that electron, the sodiu ion now has an octet of electrons from the second energy level and a charge of 1+ . The electron arrangement of the sodium ion is now the same as that of the noble gas neon. Consider a similar process with magnesium and aluminum. In this case, the magnesium atom loses its two valence electrons in order to achieve the same arrangement as the noble gas neon and a charge of 2+ . The aluminum atom loses its three valence electrons to have the same electron arrangement as neon and a charge of 3+ . For representative elements under typical conditions, three electrons is usually the maximum number that will be los. Representative elements will not lose electrons beyond their valence because they would have to "break" the octet of the previous energy level which provides stability to the ion. Anions Anions are the negative ions formed from the gain of one or more electrons. When nonmetal atoms gain elections, they often do so until their outermost principal energy level achieves an octet. For fluorine, which has an electron arrangement of (2, 7), it only needs to gain one electron to have the same electron arrangement as neon. Forming an octet (eight electrons in the outer shell) provides stability to the atom. Fluorine will gain one electron and have a charge of 1− . The electron arrangement of the fluoride ion (2, 8) will also change to reflect the gain of an electron. Oxygen has an electron arrangement of (2, 6) and needs to gain two electrons to fill the n=2 energy level and achieve an octet of electrons in the outermost shell. The oxide ion will have a charge of 2− as a result of gaining two electrons. Under typical conditions, three electrons is the maximum that will be gained in the formation of anions. Subatomic Particles in an Ion Since ions form from the gain or loss of electrons, we can also look at the number of subatomic particles (protons, neutrons, and electrons) found in an ion. Remember that the number of protons determines the identity of the element and will not change in a chemical process. Example 2.5.1 How many protons, neutrons, and electrons in a single oxide (O2−) ion? Solution Oxygen has the atomic number 8 so both the atom and the ion will have 8 protons. The average atomic mass of oxygen is 16. Therefore, there will be 8 neutrons (atomic mass−atomic number=neutrons) . A neutral oxygen atom would have 8 electrons. However, the anion has gained two electrons so O2− has 10 electrons. We can also use information about the subatomic particles to determine the identity of an ion. Example 2.5.2 An ion with a 2+ charge has 18 electrons. Determine the identity of the ion. Solution If an ion has a 2+ charge then it must have lost electrons to form the cation. If the ion has 18 electrons and the atom lost 2 to form the ion, then the neutral atom contained 20 electrons. Since it was neutral, it must also have had 20 protons. Therefore the element is calcium. Polyatomic Ions A polyatomic ion is an ion composed of two or more atoms that have a charge as a group (poly = many). The ammonium ion (see figure below) consists of one nitrogen atom and four hydrogen atoms. Together, they comprise a single ion with a 1+ charge and a formula of NH+4 . The hydroxide ion (see figure below) contains one hydrogen atom and one oxygen atom with an overall charge of 1− . The carbonate ion (see figure below) consists of one carbon atom and three oxygen atoms and carries an overall charge of 2− . The formula of the carbonate ion is CO2−3 . The atoms of a polyatomic ion are tightly bonded together and so the entire ion behaves as a single unit. The figures below show several examples. Soult Screenshot 2-2-1.png Figure 2.5.1 : The ammonium ion (NH+4) is a nitrogen atom (blue) bonded to four hydrogen atoms (white). Soult Screenshot 2-2-2.png Figure 2.5.2 : The hydroxide ion (OH−) is an oxygen atom (red) bonded to a hydrogen atom. Soult Screenshot 2-2-3.png Figure 2.5.3 : The carbonate ion (CO2−3) is a carbon atom (black) bonded to three oxygen atoms. The table below lists a number of polyatomic ions by name and by structure. The heading for each column indicates the charge on the polyatomic ions in that group. Note that the vast majority of the ions listed are anions - there are very few polyatomic cations. 1− 2− 3− 1+ Table 2.5.1 : Common Polyatomic Ions acetate, CH3COO− carbonate, CO2−3 arsenate, AsO3−3 ammonium, NH+4 bromate, BrO−3 chromate, CrO2−4 phosphite, PO3−3 chlorate, ClO−3 dichromate, Cr2O2−7 phosphate, PO3−4 chlorite, ClO−2 hydrogen phosphate, HPO2−4 cyanide, CN− oxalate, C2O2−4 dihydrogen phosphate, H2PO−4 peroxide, O2−2 hydrogen carbonate, HCO−3 silicate, SiO2−3 hydrogen sulfate, HSO−4 sulfate, SO2−4 hydrogen sulfide, HS− sulfite, SO2−3 hydroxide, OH− hypochlorite, ClO− nitrate, NO−3 nitrite, NO−2 perchlorate, ClO−4 permanganate, MnO−4 The vast majority of polyatomic ions are anions, many of which end in -ate or -ite. Notice that in some cases such as nitrate (NO−3) and nitrite (NO−2) , there are multiple anions that consist of the same two elements. In these cases, the difference between the ions is the number of oxygen atoms present, while the overall charge is the same. As a class, these are called oxyanions. When there are two oxyanions for a particular element, the one with the greater number of oxygen atoms gets the -ate suffix, while the one with the fewer number of oxygen atoms gets the -ite suffix. The four oxyanions of chlorine are shown below, which also includes the use of the prefixes hypo- and per-. ClO− , hypochlorite ClO−2 , chlorite ClO−3 , chlorate ClO−4 , perchlorate Not your usual ion Soult Screenshot 2-2-4.png "Drink you milk. It's good for your bones." We're told this from early childhood, and with good reason. Milk contains a good supply of calcium, part of the structure of bone. However, there are two other ionic components of hydroxyapatite, the mineral component. Phosphate ion and hydroxide ion make up the remainder of the inorganic material in bone. News You Can Use Bone is a very complex structure. It is composed of protein (mainly collagen), hydroxyapatite (a calcium-phosphate-hydroxide mixture), some other minerals, and contains 10 - 20% water. The calcium/phosphate ratios are not stoichiometric, but vary somewhat from one portion of bone to the next. Bones are very strong but will break under enough stress. Regular exercise and proper nutrition help to increase bone strength. Watch a video about bone structure at http://www.youtube.com/watch?v=d9owEvYdouk Nitrate is an anion with a complex bonding structure. Major sources for this ion in drinking water are runoff from fertilizer, septic tank leakage, sewage, and natural deposits. High concentrations of nitrates represent a significant health hazard, especially to infants. The nitrate in the body is converted to nitrite, which then binds to hemoglobin. This binding decreases the ability of hemoglobin to transport oxygen, thus depriving the cells of the O2 needed for proper functioning. Cyanide production is widespread throughout nature. Forest fires will produce significant amounts of cyanide. Many plants contain cyanide, and it is produced by a number of bacteria, algae, and fungi. Cyanide is used industrially in metal finishing, iron and steel mills, and in organic synthesis processes. This material is also an important component for the refining of precious metals. Formation of a complex between cyanide and gold allows extraction of this metal from a mixture.

• Agriculture is growing of crops and keeping of animals. • People who practice agriculture are called farmers. • Agriculture is very important to the family. Benefits to the family • It provides food. • It provides money. • Agriculture gives us medicine. • It provides jobs. • Agriculture gives us transport and power. • It helps most families become self sufficient. • Farm tools are instruments used on farms to make work easier. • They are usually handheld and are used frequently when practicing agricultural activities. • Farm tools are light in weight, easy to handle and are suited to the strength of the farmer Name of tool Picture Use Watering can For fine watering of seed beds bucket Carrying manure, fertilizer,seed and ripe crops Name of tool Picture Use Sickle Cutting grass and harvesting of cereals like rice and wheat Slasher Cutting down tall grass and weeds USES OF FARM TOOLS Name of tool Picture Use Garden trowel Transplanting seedlings and making planting holes Hand fork Shallow cultivation of soil Aerating the soil USES OF FARM TOOLS Name of tool Picture Use Shovel Loading and offloading soil or manure into a wheelbarrow, scotch cart or truck Spade Digging and turning over of moist soil USES OF FARM TOOLS Name of tool Picture Use Garden fork Loosening and turn soil Garden line Marking straight ridges and garden beds USES OF FARM TOOLS Name of tool Picture Use wheelbarrow Moving items around the farm Items such as soil, mulch, animal feed. Etc Knapsack sprayer Spraying pesticides and herbicides Spraying fertilizers on crops. • An inventory is a record of the things that you have. • This is a list of tools issued out and tools received back and from whom Inventory of farm tools Inventory record sheets Created by Date Name of tool Sheet Tool numbenumber Description r Location Quantity Spade 1/15 Black,wooden handle Store room 2 SAFETY IN AGRICULTURE • Agricultural activities can be dangerous. • Hazards involved results in injury, disability and death of people and animals. • The hazards are usually caused by physical injury and chemical poisoning. Common hazards in Agriculture 1. physical injury These include: • Injury caused by accidents during use of farm tools, equipment and machinery. • Misuse and improper storage of farm tools and equipment. • Being kicked by animals. • Drowning in farm pond, pool or dam. Common hazards in Agriculture 2 . Chemical poisoning These include: • Spraying without protective clothing. • Eating or smoking when spraying chemicals. • Dumping toxic chemical left overs on land and in water. • Eating agriculture produces without prior permission from adults. • Pesticides, herbicides and fertilizers pollute water sources and kill animals. Chemical poisoning Ways of preventing common agricultural hazards 1. Wear protective clothing such as gloves, gumboots, respirator, hat and overalls. 2. Do not eat, drink or smoke when spraying. 3. Dispose off all chemical remains safely. 4. Bury or burn empty chemical containers and chemical left overs. 5. Wash thoroughly with running water and soap after using chemicals. 6. Do not spray during windy days. 7. Handle tools the right way. 8. Fence farm ponds and dams. Ways of preventing common agricultural hazards Climate and Landuse Seasons of Zimbabwe Seasons of Zimbabwe Definition of terms • A season is a time of the year with almost the same weather patterns. • Weather is the state of the atmosphere at a particular time at a particular place. • it is the daily condition of air around us. • Seasons are determined by rainfall and temperature. Seasons of Zimbabwe • There are four seasons in Zimbabwe , which are: 1.The rain season 2.Post rain season 3.Cool dry season 4.Hot dry season Seasons of Zimbabwe 1.The rain season ( summer) • It is also called the hot- wet season. • The season begins in mid November to mid March. • The period is rainy and hot. • Dams and rivers fill up. Seasons of Zimbabwe 2 . The post rain season ( autumn ) • It starts mid March – May • The days are bright and sunny. • The leaves change from green to red, orange, yellow or brown before falling. • In addition, there is less sunlight because the days are shorter. • It is the harvesting period of most crops. Seasons of Zimbabwe 3. The cold dry season ( winter ) • It begins mid May – mid August • The mornings, evenings and nights are very cold. • Has short days and long nights. Seasons of Zimbabwe 4 . The hot season (spring ) • It begins mid August – mid November. • The days are very hot with cool nights. • A season for trees to develop new shoots. Summer Activities Agricultural activities done during the rain season includes: • Ploughing and planting of summer crops for example maize, cotton. • Weeding • Pest and disease control • Applying fertilizers. • Weekly dipping of animals because ticks, lice and mites would be many. • Harvesting of summer crops • Preparing fireguards. A fireguard is a fire break. • Beginning of the planting of wheat, barley and oats. Winter Activities • Planting of winter crops such as wheat, barley and oats. • Harvesting and selling of summer crops continues. • Constructing frost barriers for frost sensitive crops such as tomatoes. • Vaccinating animals against blackleg. • Supplementary feeding of grazing animals. • Dosing of animals to kill internal parasites. Spring Activities • Shelling and threshing of grain crops. • Dry planting of summer crops. • Carrying manure to fields. • Ploughing and harrowing. • Making planting holes Soil Components •Soil is made up of 4 components: 1)Mineral matter 2)Organic matter 3)Soil water 4)Soil air

•There are two type of fruit trees namely indigenous and exotic trees. Indigenous trees: • these are fruit trees that grow naturally in an area. •Examples of indigenous trees are baobab, wild loquat, sugar apple, mobola plum and cape figs. Exotic trees: • These are trees which originally grew in other countries and are being grown in Zimbabwe. • Examples of these are oranges, naartjies, bananas, paw paws and avocado. Propagating fruit trees •There are different ways of multiplying or propagating fruit trees. •These include seeds, cuttings and grafting. Seeds: •Indigenous trees usually grow on their own. •They grow from seeds. •The early stages of a growing seed is called germination. •Fruit trees seeds are planted differently from field crops or vegetables. •The seeds are raised in a nursery or individually in containers or polythene pockets. sowing of the seed •Seed boxes, pots or polythene pockets should be filled with soil mixed with organic matter. •Leave about 20mm above the soil for water to collect when watering. •The polythene pocket should be punctured around and beneath to allow water drainage. Cuttings •A cutting is a piece of plant such as a stem, root or leaf that is placed in moist soil. •it will then grow the missing parts to produce a full plant under the right conditions •Mulberry, guavas, granadillas, figs, grapes and apples can be grown using cuttings. Grafting or budding •This is when you slice a piece from one plant and join it onto another plant. •The joining or grafting of these two plants will then grow as a single plant. •It is whereby the upper part (scion) of one plant grows on the root system (root stock) of another plant of another plant

Create a quiz over the following topic: Visual Art: Elements of Art, Music, Dance, and Drama A. Elements of Visual Art: There are seven primary elements of art (line, shape, form, space, color, value, texture), the components from which any artwork can be built. Any artwork that can stand the test of time will contain these elements. Element 1 – Line Line is the most fundamental concept in art. This element leads the viewer’s eye around the artwork, communicating the piece’s meaning to the viewer. Without this element, none of the other elements could exist. At its most basic foundation, a line is simply a moving dot. When these dots overlap, the line is solid. When they do not overlap, the line is dotted or dashed. These “incomplete” lines can represent movement or hidden material behind the primary figure. Repeated lines create patterns, and these patterned lines create a rhythm for the work. Lines can be: • Curved • Zigzag • Horizontal • Vertical • Diagonal • Implied • Gesture • Varied thicknesses • Varied lengths Examples of lines and their meaning in art: Thick Lines – give emphasis and advance Thin Lines – recede and cause the eye to “lose interest” Straight Lines – rarely found in nature, thus are inorganic. Straight lines are dynamic and mechanistic. Curved Lines – gently change directions and have no sharp angles, suggesting calmness – Curved lines are more readily found in nature and are thus considered organic lines Works with pronounced curved lines include Van Gogh’s The Starry Night (1889). Note the movement across the sky.

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