Mention the

Rules for writing a chemical equation:

(i) The method of representing a chemical reaction with the help of symbols and formulae of the substances involved in it is known as a chemical equation.

(ii) The substances which combine or react are known as reactants.

(iii) The new substances produced in a reaction are known as products

(iv) The arrow sign (→) pointing towards the right hand side is put between the reactants and products.

This arrow indicates that the substance written on the left hand side are combining to give the substance written on the right hand side in the equation.

For example:

Zinc metal reacts with dilute sulphuric acid to form zinc sulphate and hydrogen gas.

Zinc + Sulphuric acid Zinc Sulphate + Hydrogen

Putting the symbols and formulae of all the substances in the above words gives equation,