Explain why physical changes can easily be reversed but chemical changes cannot

Physical changes can easily be reversed but chemical changes cannot because in physical change only state is changed while in chemical change, new substances are formed. For example, when water in liquid form is condensed, it changes into solid form (ice). It is a physical change because water in liquid and solid have the same chemical formula only arrangement of molecules are different. Burning of wood is a chemical change because new substances i. e. carbondioxide and heat is produced.