Matter is one of those simple concepts that is very tough to define. Some of the unique properties of matter include:
Also weak charge. But, gluons have color, and weak bosons have mass. Are you counting those as matter? Maybe a better way to define matter would be in terms of fermions.
Some properties that matter shares with Energy include:
- it can behave as both a particle and a wave
- it can carry both momentum and angular momentum
Matter the matter that we observe most commonly takes the form of compounds, polymers, alloys, or pure elements.
Matter exists in "states", the most familar of which are solid, liquid, and gas. Others include plasma, superfluid, and Bose-Einstein condensate
See also: antimatter, Phases of matter, particle physics