* Particles are held together by strong forces of attraction.

* Particles are packed tightly together.

* Particles do not move around very much.

* Solids have a definite shape and volume.

Liquids

* Particles are held together by weaker forces of attraction than in solids.

* Particles are not packed as tightly together as in solids.

* Particles can move around more easily than in solids.

* Liquids do not have a definite shape, but they do have a definite volume.

Gases

* Particles are held together by very weak forces of attraction.

* Particles are not packed together at all.

* Particles can move around very easily.

* Gases do not have a definite shape or volume.