What happens in an oxidation reaction?

Oxidation reaction:

• When oxygen combines with an element or compound, an oxidation reaction occurs.
• Oxidation can also be defined as the process of the removal of hydrogen from the reactant species.
• Oxidation is the process of losing electrons by a molecule, atom, or ion. For example, $\mathrm{Mg}\to {\mathrm{Mg}}^{2+}+2{\mathrm{e}}^{-}$

Example of Oxidation reaction:

• When iron reacts with oxygen to form iron oxide. This reaction is known as an oxidation reaction

$4\mathrm{Fe}\left(\mathrm{s}\right)+3{\mathrm{O}}_2\left(\mathrm{g}\right)\to 2{\mathrm{Fe}}_2{\mathrm{O}}_3\left(\mathrm{s}\right)$