Matter can change its state when energy in the form of heat is either absorbed or released. Identify the 3 state changes below that are endothermic. Choose 3 correct answers. Explain.

Question

a
deposition
b
sublimation
c
freezing
d
vaporization
e
melting
f
condensation

Answer 1

The three state changes that are endothermic are:
1. Melting: This is the process of a solid changing into a liquid. It is endothermic because energy in the form of heat is absorbed to break the bonds between the particles in the solid, allowing them to move and flow freely as a liquid.
2. Vaporization: This is the process of a liquid changing into a gas. It can occur either through boiling (at a specific temperature) or evaporation (below boiling point). Vaporization is endothermic because energy in the form of heat is absorbed to overcome the intermolecular forces holding the liquid particles together and convert them into a gas.
3. Sublimation: This is the process of a solid directly changing into a gas, without going through the liquid phase. Sublimation is endothermic because energy in the form of heat is absorbed to break the bonds between the particles in the solid and convert them into a gas, without passing through a liquid phase.