Matter can be classified by its state.Solids have a set volume and shape.The inter molecular force of attraction for solid matter is very strong.Liquids have a set volume, but change shape. The inter molecular force of attraction for liquid matter is weaker than solid matter.Gases have neither definite volume nor shape. The inter molecular force of attraction for gaseous matter is negligible.Plasma which are usually gaseous state of matter in which a part or all of the atoms or molecules are dissociated to form ions.