What Is Matter? Definition and Examples

Matter has mass and occupies volume.
Matter has mass and occupies volume.

What is matter? In science, matter is defined as any substance that has mass and takes up space. Basically, it’s anything that can be touched. Yet, there are also phenomena that are not matter, such as light, sounds, and other forms of energy. A space devoid of all matter is called a vacuum.

Examples of Matter

Anything you can touch, taste, or smell consists of matter. Examples include:

  • Atoms
  • Ions
  • Molecules
  • Furniture
  • People
  • Plants
  • Water
  • Rocks

You can observe things which are not matter. Typically, these are forms of energy, such as sunlight, rainbows, thoughts, emotions, music, and radio waves.

States of Matter

You can identify matter by its chemical composition and its state. States of matter encountered in daily life include solids, liquids, gases, and plasma. Other states of matter exist near absolute zero and at extremely high temperatures.

  • Solid – State of matter with a defined shape and volume. Particles are packed close together. Example: Ice
  • Liquid – State of matter with defined volume, but no defined shape. Space between particles allows this form of matter to flow. Example: Water
  • Gas – State of matter without a defined volume or shape. Particles can adjust to the size and shape of their container. Example: Water vapor in clouds

Difference Between Matter and Mass

The terms “matter” and “mass” are related, but don’t mean exactly the same thing. Mass is a measure of the amount of matter in the sample. For example, you might have a block of carbon. It consists of carbon atoms (a form of matter). You could use a balance to measure the block’s mass to obtain a mass in units of grams or pounds. Mass is a property of a sample of matter.

What Is Matter Made Of?

Matter consists of building blocks. In chemistry, atoms and ions are the smallest units of matter that cannot be broken down using any chemical reaction. But, nuclear reactions can break atoms into their subunits. The basic subunits of atoms and ions are protons, neutrons, and electrons. The number of protons in an atom identifies its element.

Protons, neutrons, and electrons are subatomic particles, but there are even smaller units of matter. Protons and neutrons are examples of subatomic particles called baryons, which are made of quarks. Electrons are examples of subatomic particles called leptons. So, in physics, one definition of matter is that it consists of leptons or quarks.

Matter vs Antimatter

Antimatter consists of antiparticles. Antimatter is still matter, but while ordinary matter consists of leptons and baryons with a positive number, antimatter consists of leptons and baryons with a negative number. So, there are antielectrons (called positrons), antiprotons, and antineutrons.

Antimatter occurs in the world. For example, lightning strikes, radioactive decay, and cosmic rays all produce antimatter. When antimatter encounters ordinary matter, the two annihilate each other, releasing a lot of energy. But, this isn’t the universe-ending event you see in science fiction. It happens all the time.

Matter vs Dark Matter

Matter made from protons, neutrons, and electrons is sometimes called ordinary matter. Similarly, a substance made of leptons or quarks is ordinary matter. Scientists estimate about 4% of the universe consists of ordinary matter. About 23% is made of dark matter and 73% consists of dark energy. The simplest definition of dark matter is that it consists of non-baryonic particles.

Dark matter is one form of what physicists call “exotic matter.” Other types of dark matter may exist, potentially with bizarre properties, such as negative mass!


  • de Podesta, M. (2002). Understanding the Properties of Matter (2nd ed.). CRC Press. ISBN 978-0-415-25788-6.
  • Olmsted, J.; Williams, G.M. (1996). Chemistry: The Molecular Science (2nd ed.). Jones & Bartlett. ISBN 978-0-8151-8450-8.
  • Tsan, U.C. (2012). “Negative Numbers And Antimatter Particles”. International Journal of Modern Physics E. 21 (1): 1250005–1–1250005–23. doi:10.1142/S021830131250005X

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