Answer : In a balanced equation, the number of each type of atom on the reactant side must be equal to the number of each type of atom on the product side.
Explanation :
Balanced chemical reaction : It is defined as the number of atoms of individual elements present on reactant side must be equal to the number of atoms of individual elements present on product side.
For example :
The unbalanced chemical reaction is,
This chemical reaction is an unbalanced reaction because in this reaction, the number of atoms of iron are not balanced while all the atoms are balanced.
In order to balanced the chemical reaction, the coefficient 2 is put before the 'Fe'.
Thus, the balanced chemical reaction will be,