|P6: RADIOACTIVE MATERIALS||Physics|
|All elements are made of one type of atom. All atoms contain a nucleus and electrons. The nucleus is made from protons and neutrons. With the exception of Hydrogen (lightest element) which has just one proton and electron.||HT: Every atom of a particular element will have the same number of protons. (If not it would be a different element) However, some atoms of the same element can have different numbers of neutrons. These are called isotopes. E.G Oxygen-16 and Oxygen-18|
|Radioactive materials can emit three types of ionising radiation: Alpha Beta Gamma|
|Radioactive Decay: Ionising radiation is emitted when the nucleus of an unstable atom decays. The type of radioactive decay depends on why the nucleus is unstable. The process of decay helps helps the atom become stable. During this the proton number may change causing the element to change type.||
(A)The atom decays to become stable. It ejects an alpha particle. Leaving it with 2 protons and neutrons less. Ionising radiation is given off.
Image: alphadecay.gif (image/gif)
(B) The atom converts a neutron into a proton and an electron. The electron is ejected. Proton stays in nucleus changing element.
Image: beta_decay (image/png)
(G) After alpha or beta decay there is sometimes surplus energy. This is emitted as gamma radiation. (Electromagnetic and high frequency)
Image: gamma (image/jpg)
|Background Radiation: Radioactive elements are found naturally in the environment and contribute to background radiation. The levels are usually so low there is no danger. However there are correlations with certain cancers and living in specific areas.||Irradiation: When a person is exposed to radiation. Contamination: When radioactive material is on a persons skin, clothes or has entered their body.|