Atomic Structure

2. Type of radiation which can travel up to 1 metre in air.
3. An atom which has lost (or gained) electrons.
5. Measured in Becquerels (Bq).
7. Atoms with the same number of protons.
9. Atoms with the same number of protons (same element) but different number of neutrons.
10. The ……… number is the number of protons and neutrons in the nucleus of an atom.
12. What have a radius of about 1 × 10-10 metres?
14. An alpha particles consists of two protons and two…?
15. What do unstable nuclei emit (give out)?

1. The time taken for half of the unstable nuclei of a radioactive isotope to decay.
4. Where are the protons and neutrons found in an atom?
6. A beta particle is a high speed…?
8. Type of radiation which stopped by several centimetres of lead or thick concrete
11. Radioactive decay is a ……. process because you can’t tell which nucleus will decay next.
13. The ……… number is number of protons in the nucleus of an atom.
16. Type of radiation which is most ionising (damaging)