Chemical reaction and equation
Chemical Reaction: The transformation of chemical substance into another chemical substance is known as Chemical Reaction. For example: Rusting of iron, the setting of milk into curd, digestion of food, respiration, etc. In a chemical reaction, a new substance is formed which is completely different in properties from the original substance, so in a chemical reaction, a chemical change takes place. Only a rearrangement of atoms takes place in a chemical reaction. · The substances which take part in a chemical reaction are called reactants. · The new substances produced as a result of a chemical reaction are called products. Example: The burning of magnesium in the air to form magnesium oxide is an example of a chemical reaction. 2Mg(s) + O 2 (g) △ → 2MgO(s) Before burning in air, the magnesium ribbon is cleaned by rubbing with sandpaper. This is done to remove the protective layer of basic magnesium carbonate from the surface of the magnesium ribbon.