Radiation

1. The time taken for half of the unstable nuclei of a radioactive isotope to decay.
4. An atom which has lost (or gained) electrons.
6. A beta particle is a high speed…?
8. The ________ number is number of protons in the nucleus of an atom.
11. Type of radiation which is stopped by several cms of lead or thick concrete
13. Where the protons and neutrons are found in an atom
14. What do unstable nuclei emit (give out)?
15. The ________ number is the number of protons and neutrons in the nucleus of an atom.

2. Same element so the same number of protons but different number of neutrons.
3. An alpha particles consists of two protons and two…?
5. What has a radius of about 1 × 10-10 metres?
7. All of the atoms of an ________ have the same number of protons.
9. Radioactive decay is a ________ process because you can’t tell which nucleus will decay next.
10. Type of radiation which can travel up to 1 m in air
12. Type of radiation which is the most ionising (damaging)