Here's why:

* Combustion is a chemical process that involves the rapid reaction between a substance with an oxidant, usually oxygen, to produce heat and light.

* In this case, methane (CH4) reacts with oxygen (O2) to produce carbon dioxide (CO2) and water (H2O), releasing energy in the form of heat and light.

The complete balanced chemical equation for the combustion of methane is:

CH4 + 2O2 → CO2 + 2H2O