An
atom can be thought of as a small nucleus surrounded by orbiting electrons.
The nucleus of the atom contains particles called protons and neutrons.
The diagram (left) is simplified.
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 radiation is slow moving helium nuclei
- Beta radiation is fast moving electrons
- Gamma radiation is high-energy electromagnetic waves.
The three radiations transfer energy from the nucleus when they are emitted.
[ This page has been adapted from www.bbc.co.uk/schools/gcsebitesize/science
]