Question

What is an endothermic reaction?

Answer 1

A reaction where energy is taken in from the surroundings causing temperature to decrease. Bond breaking requires energy and bond making releases energy. Therefore, if energy is taken in from the environment then in that reaction, more bonds are broken than formed. e.g. melting an ice cube.

Answer 2

Endothermic reactions are reactions that take in energy. This is usually in the form of heat. An example could be evaporation because heat is being absorbed by water and molecules are moving away from each other.