- Matter describes the physical substances around us – such as solids, liquids, and gases.
- Matter is made up of atoms, which may combine to form molecules.
- Subatomic particles have mass and may have energy.
- Matter can undergo physical and chemical changes, but the total amount of matter in a closed system remains constant (Law of Conservation of Matter).
- Light is a form of electromagnetic radiation, which does not have mass and is not considered matter.
- Einstein’s equation E=MC2 suggests that mass and energy are interchangeable, and one can be converted to the other.