Answer:
Heat as a reactant makes the change endothermic, while heat as a product makes the change exothermic.
Explanation:
In an endothermic reaction, heat is a reactant, making the endothermic reaction cooler than its surroundings. This can be compared to how an ice cube melting requires heat as a reactant.
In an exothermic reaction, heat is a product, making the exothermic reaction hotter than its surroundings. This is compared to how a fire releases heat into the air as a product.
