Answer the following question given this paragraph: 

If particles have enough kinetic energy to completely overcome the force of attraction between them, matter exists as a gas. The particles can pull apart and spread out. This explains why gases have neither a fixed volume nor a fixed shape.


Q: If particles have enough kinetic energy to completely overcome the force of attraction between them, matter exists as a what?

 Choices:

- liquid

- solid

- vapor

- gas

A:
gas
