Answer the following question given this paragraph: 

Chemical energy, the energy stored in molecules and atoms, is one type of potential energy. Certain reactions can cause this energy to be released as heat. Other reactions require an input of energy, in which case the products will store more potential energy than the reactants. When we studied phase changes, we saw a relationship between energy and the state of matter. To melt a solid or boil a liquid, energy needs to be added in order to break up the intermolecular forces holding particles together in more ordered states. The reverse processes, condensation and freezing, release energy, because more favorable intermolecular interactions are formed.


Q: Which forces hold particles together in more ordered states?

 Choices:

- natural

- gravitational

- particular

- intermolecular

A:
intermolecular
