Nuclear radiation

There are three main types of ionising radiation emitted from the unstable nuclei of radioactive atoms - these are alpha, beta and gamma radiation.

Alpha radiation

Alpha radiation consists of alpha particles. An alpha particle is identical to the nucleus of a helium atom, which comprises two protons and two neutrons.

Helium atom

Helium atom with two neutrons and two protons in the nucleus and two electrons orbiting.

2 protons

2 neutrons

2 electrons

Alpha particle

An alpha particle which has two neutrons and two protons.

2 protons

2 neutrons

0 electrons

Beta radiation

Beta radiation consists of high energy electrons emitted from the nucleus. These electrons have not come from the electron shells or energy levels around the nucleus. Instead, they form when a neutron splits into a proton and an electron. The electron then shoots out of the nucleus at high speed, leaving the new proton behind in the nucleus.

Gamma radiation

Gamma radiation is very short wavelength, high frequency electromagnetic radiation. This is similar to other types of electromagnetic radiation, such as visible light and X-rays, which can travel long distances.