How is an endothermic reaction identified? A. It has a large heat capacity.
B. It gives off heat as a product.
C. It requires heat as a reactant.
O D. It results in a phase change.

Heat is involved in chemical change in two ways; chemical changes either result in heat being added to or removed from an object, and chemical changes require a certain amount of heat before they can take place.

Answerhund's rule;