Compounds are formed from chemical reactions.
A chemical reaction is formed when atoms of the reactants break free to bond again and form products.
A chemical reaction is a statement showing the movement of reactants to form products.
The following procedure is used in writing a chemical equations:
1. Write the word equation.
2. Write the correct chemical formula for each of the reactants and products.
3. Check if the number of atoms of each element on the reactant side is equal to the number of atoms of each element on the product side.
4. Multiply the chemical formula containing the unbalanced atoms with the lowest common multiple if the number of atoms on one side is not equal. This is called balancing. Do not change the chemical formula of the products/reactants.
5. Assign in brackets, the physical state/state symbols of the reactants and products after each chemical formula as:
(i) (s) for solids.
(ii) (l) for liquids.
(iii) (g) for gas.
(iv) (aq) for aqueous/dissolved in water to make a solution.