- Endothermic reactions are chemical reactions in which the reactants absorb heat energy from the surroundings to form products.
- A system of reactants that absorbs heat from the surroundings in an endothermic reaction has a positive ΔH.
- examples of endothermic processes:

Melting ice cubes.
Melting solid salts.
Sublimation of dry ice into carbon dioxide gas.
Evaporating liquid water.