d is an easily available source of chemical energy. Since ancient times, wood has been burnt to give out heat and energy. The wood decomposes to produce chemical energy.CoalThe most basic source of chemical energy is coal. Coal is formed when excessive heat and pressure under the Earth surface act upon rocks for millions of years. Coal is BURNED to obtain chemical energy.GasolineThe gasoline that we USE in cars is also a source of chemical energy. The gasoline is burned in the combustion chamber of the engine to produce chemical energy.PhotosynthesisPhotosynthesis is the process by which PLANTS convert the sun energy they receive into chemical energy. It involves chemical reactions in which the sun energy is trapped by the plant molecule and then CHANGED into chemical energy to be used in the form of glucose for consumption.ElectrolysisElectrolysis is the process where an electrolyte (a substance UNDERGOING electrolysis) is decomposed using electricity to produce different products. The electric energy passed through the electrolyte is converted into chemical energy through different chemical reactions.