Radiation

2. Atoms of an element with the same numbers of protons, but different numbers of neutrons.
3. Spectrum A spectrum of light that includes black lines caused by some wavelengths being absorbed by materials that the light passes through.
6. Spectrum A set of wavelengths of light showing which waves have been given out (emitted) by a substance.
7. Radiation Ionising radiation that is around us all the time from a number of sources.
9. An atom or group of atoms with an electrical charge due to the gain or loss of electrons.

1. The central part of an atom.
4. A particle found in the nucleus of an atom with a positive charge and the same mass as a neutron.
5. A particle found in the nucleus of an atom with a neutral charge and the same mass as a proton.
6. A tiny particle with a negative charge and very little mass.
8. tube A device that can detect ionising radiation and is used to measure the activity of a radioactive source.