Types of radiation

The nuclei of the atoms in some elements are unstable and emit radiation. The radiation can be of three types - alpha radiation, beta radiation and gamma radiation.

  • Alpha ( \alpha) particles are slow moving helium nuclei.
  • Beta ( \beta) particles are fast moving electrons.
  • Gamma ( \gamma) rays are high-energy electromagnetic waves.

The three radiations transfer energy from the nucleus when they are emitted.

This video explains what ionising radiation is and how a radioactive substance decays over time according to its half-life. You can read more about the process of radioactive decay later in this section.

Nuclear half-life