What is Radiation?

Radiation is energy that comes from a source and travels through space at the speed of light. This energy has an electric field and a magnetic field associated with it, and has wave-like properties. You could also call radiation “electromagnetic waves”.

The Electromagnetic Spectrum

Illustration of electromagnetic spectrum
  • There is a wide range of electromagnetic radiation in nature. Visible light is one example.
  • Radiation with the highest energy includes forms like ultraviolet radiation, x-rays, and gamma rays.
  • X-rays and gamma rays have a lot of energy. When they interact with atoms, they can remove electrons and cause the atom to become ionized.

Learn more about the electromagnetic spectrum

The Ionized Atom

illustration of radioactive atom
  • Radioactive atoms have unstable blends of protons and neutrons.
  • Radioactivity is the spontaneous release of energy from an unstable atom to get to a more stable state.
  • Ionizing Radiation is the energy that comes out of a radioactive atom.
  • Radioactive isotopes are radioactive atoms of the same element that have different numbers of neutrons.

Learn more about how radioactive atoms work

Properties of Radioactive Isotopes

illustration of alpha particle
  • Radioactive atoms can give off four types of ionizing radiation: alpha particles, beta particles, gamma rays, and neutrons.
  • Each type of radiation has different properties. Their properties affect how we can detect it and how it can affect us.
  • An unstable atom changes into a more stable atom of a different element by giving off radiation. This process is called radioactive decay.
  • A half-life is the length of time it takes for half of the radioactive atoms in a group of radioactive isotopes to decay.

Learn more about properties of radioactive isotopes

Page last reviewed: May 17, 2022