Some examples of exothermic processes are:
* Combustion of fuels such as wood, coal and oil/petroleum
* The thermite reaction
* The reaction of alkali metals and other highly electropositive metals with water
* Condensation of rain from water vapor
* Mixing water and strong acids or strong bases
* The reaction of acids and bases
* Dehydration of carbohydrates by sulfuric acid
* The setting of cement and concrete
* Some polymerization reactions such as the setting of epoxy resin
* The reaction of most metals with halogens or oxygen
* Nuclear fusion in hydrogen bombs and in stellar cores (to iron) 
* Nuclear fission of heavy elements
* The reaction between zinc and hydrochloric acid
* Respiration (breaking down of glucose to release energy in cells)