Question

When does matter actually undergo a change of state?

Answer 1

1. All particles have energy.
2. The energy varies depending on the temperature of the substance.
3. This in turn determines whether the substance exists in the solid, liquid, or gaseous state.
4. Molecules in the solid phase have the least amount of energy, while gas particles have the greatest amount of energy.
5. A change in phase may occur when the energy of the particles is changed.

Thus, matter undergoes a change of state when the energy of the particles in the matter is changed.