Step 1:

Oxidation process:

An oxidation is defined as loss of electrons in the process of a chemical reaction.

If a species gains electrons, it is undergoing a reduction.

Oxidation is process where the oxidation number increases.

Oxidation numbers are assigned to elements as follows :

1. The oxidation number of a element in its free state is always zero.

2. The oxidation number of a monotonic ion is same as the charge of the ion.

3. The sum of all oxidation numbers in a neutral compound is zero.

Step 2:

Consider a oxidation - reduction reaction.

Example: .

Here Carbon (C) two gain electrons and changes its charge from +4 to +2.

Similarly Hydrogen H₂ losses one electron and changes its charge from 0 to +1.

Hence Hydrogen is oxidized and carbon is reduced.

Solution:

Oxidation is process where the oxidation number increases.