In any reaction, as per the law of conservation of mass, the total mass of each of the elements in the reactants is equal to the total mass of each of the respective elements in the products. If the number of atoms of the elements in the reactants of the equation and the number of atoms of those elements in the products is the same, then it is a ‘balanced equation’. If the number of atoms of each element is not the same on the two sides of an equation, it is an ‘unbalanced equation’.

A chemical equation is balanced step by step.

Derive the chemical equation from the given word equation.

See if the equation is balanced or unbalanced by comparing the number of atoms of the various elements present on the both sides of the equation

Start balancing an equation from the compound that contains the maximum number of atoms. Moreover, first consider the element in this compound that has an unequal number of atoms on both sides.

Write down the final balanced equation again.

This is the way in which a balanced equation is obtained from an unbalanced equation adapting proper factors to the appropriate reactant/product in order to balance the number of each element in steps.