How does combustion of methane involve oxidation and reduction?

The combustion of methane is a classic example of an oxidation-reduction reaction, a process where the oxidation number of participating species changes.12

In this reaction, oxidation and reduction occur simultaneously because an increase in electron density at one atom must be balanced by a decrease at another. Specifically:2

• Oxidation: The carbon atom in methane becomes oxidized as it loses electron density. This occurs because the carbon bonds to oxygen, which is more electronegative, and hydrogen atoms are removed from the carbon.2
• Reduction: The oxygen atoms involved in the reaction gain electron density, effectively undergoing reduction as they bond with the carbon and hydrogen.2

Because oxidation and reduction are inextricably linked, the combustion process—a familiar form of fire—cannot occur without both processes happening in tandem.12