Matter: Definition and Examples

Atom
An atom is a unit of matter. KTSDESIGN/SCIENCE PHOTO LIBRARY/Getty Images

There are many possible definitions of matter. In science, matter is the term for any type of material. Matter is anything that has mass and takes up space. At a minimum, matter requires at least one subatomic particle, although most matter consists of atoms. The word matter is sometimes used to refer to a pure substance.

Examples of Matter

Matter can include any of the following (and more, of course):

  • Proton
  • Atoms (e.g., a helium atom)
  • Molecules (e.g., water, sugar)
  • Compounds (e.g., table salt, silicon dioxide)
  • Cat
  • Tree
  • House
  • Computer

Examples That Are Not Matter

Not everything we can perceive consists of matter. Examples of things that aren't matter include:

  • Photons (light)
  • Heat
  • Thoughts
  • Microwaves (the radiation, not the appliance)