Across
- 3. An equation used to represent radioactive decay.
- 6. A treatment where radiation is used to kill cancer cells
- 9. A chemical compound containing a radioactive isotope that is used to see inside bodies by detecting radiation it emits.
- 10. The level of ionisation caused by each type of nuclear decay.
- 12. The centre of an atom, consisting of protons and neutrons. It is positively charged.
- 14. The time it takes for the number of nuclei of the isotope in a sample to halve, or the time it takes for the count rate (or activity) from a sample containing the isotope to fall to half its initial level.
- 16. The continuous spectrum of electromagnetic waves. From long to short wavelength the groups are: radio, microwave, infrared, visible light, ultraviolet, X-rays and gamma rays.
- 17. The process of exposing an object to ionising radiation.
- 18. he process of releasing or giving out.
Down
- 1. The splitting of a large and unstable nucleus to form two smaller nuclei. The nucleus emits two or three neutrons plus gamma rays. Energy is released by the reaction.
- 2. The extent to which a type of radiation can be transmitted through, rather than being absorbed, by a material.
- 4. The joining of two light nuclei to form a heavier nucleus. In this process some of the mass may be converted into the energy of radiation and released.
- 5. The process of receiving or taking in.
- 7. The distance from the nucleus of an atom where electrons orbit. Also called a shell.
- 8. The radiation that is around us all of the time. It comes from: ·natural sources such as rocks and cosmic rays in space; ·humanly-constructed sources such as the fallout from nuclear weapons testing and nuclear accidents.
- 11. A self-sustaining chemical reaction in which one reaction causes further reactions, which in turn cause further reactions, and so on.
- 13. A measure of the risk of harm resulting from an exposure of the body to radiation, measured in sieverts (Sv).
- 15. The number of radioactive particles (𝜶, 𝜷 or 𝛄) recorded each second by a detector such as a Geiger-Muller tube.