Answer:
Chemical change
Step-by-step explanation:
Chemical changes occur through chemical reactions. In a chemical reactions, reactants combines together and gives new products. Chemical change is a kind of change in which new products are formed as a result of different bond combinations. They are often associated with the evolution and use of energy.
Chemical changes are not easily reversible and they require a considerable amount of energy. Examples of chemical changes are combustion, rusting of iron, precipitation e.t.c.