Physical and Chemical Changes There are two types of changes, physical and chemical changes. Physical Changes Example: Melting of ice and freezing of water. Examples of physical change: Definition of Chemical Change Chemical change is a permanent change which cannot be reversed and in which the chemical properties of a substance change with the change […]
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Acids, Bases and Salts Chemicals can be broadly classified into three categories, acids, bases and salts. Acids Examples: Hydrochloric acid and sulphuric acid are corrosive acids. Carbonic acid is a non-corrosive acid. Organic acids: Naturally occurring acids obtained from plants and animals. Mineral acids: They are obtained from minerals present in the Earth’s crust. Bases
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Wastewater Story Water – Our Lifeline Sewage Types of Impurities Examples Organic impurities Human faeces, animal wastes, oil, urea, pesticides,herbicides, fruit and vegetable wastes Inorganic impurities Nitrates, phosphates, metals Nutrients Phosphorus and nitrogen Bacteria Those which cause diseases such as cholera, dysentery andtyphoid Sources of wastewater: Treatment of sewage in cities and towns: If sewage
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Reproduction in Plants Asexual Reproduction Vegetative Propagation (a) Vegetative Propagation by Stems The stems (or branches) of plants normally bear buds in the axils which can be used in vegetative propagation to produce new plants. New plants can be obtained from the stem (or branch) of an existing plant by the method of cuttings. A
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Transportation in Animals and Plants Circulatory System Blood plasma. Blood Vessels Heart The arteries and veins in the heart connect to other parts of the body. The blood vessels that enter or leave the heart are: Vena cava: It is a large vein that collect blood rich in carbon dioxide from all parts of the
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Respiration in Organisms What is Respiration? Anaerobic Respiration in Muscles We (human beings) normally obtain energy by aerobic respiration. But under certain conditions (when extra energy is needed), anaerobic respiration can take place in our muscles for a short time. When the oxygen gets used up faster in our muscle cells than can be supplied
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Nutrition in Animals INTRODUCTION Animals get their food from plants, either directly by eating plants or indirectly by eating animals that eat plants. Some animals eat both plants and animals. Recall that all organisms including humans require food for growth, repair and functioning of the body. Animal nutrition includes nutrient requirement, mode of intake of
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Nutrition in Plants What is Nutrition? Autotrophic It is a mode of nutrition in which organisms prepare their own food. Inorganic molecules like CO2 and H2O are converted into organic molecules like carbohydrates in the presence of sunlight and chlorophyll. E.g. Green plants. Autotrophs are further categorized as: Photosynthesis Importance of Photosynthesis Synthesis of Plant
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A SHIRT IN THE MARKET Life of a Cotton Farmer The life of a cotton farmer is not easy. Many farmers who grow cotton have small farms and have to work hard to harvest the cotton crop. After harvesting the cotton, the farmers generally sell the cotton to the nearby traders. Some traders also provide
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MARKETS AROUND US We purchase the products we require from the market. There are many kinds of markets. Different Kinds of Markets Weekly Markets Shops in the Neighborhood Shopping Complexes and Malls Chain of Markets Many people are linked to the process of production, transportation and selling of goods in the markets: We find markets
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