One example is the reaction between magnesium and oxygen to form magnesium oxide, which releases heat and is both a combination reaction and exothermic.

The release of heat in a reaction mixture warms it up, altering its temperature. This thermal energy is a result of the exothermic nature of the reaction, where heat is produced during the formation of products.

Combination reactions occur when two or more substances (elements or compounds) combine to form a single product.