In a solid, particles are packed tightly together so they don't move much. Solids have a definite shape. In a liquid, the particles are more loosely packed than in a solid and are able to flow around each other, giving the liquid an indefinite shape. In a gas, the particles have a great deal of space between them and have high kinetic energy. A gas has no definite shape or volume. Plasma consists of highly charged particles with extremely high kinetic energy
