Across
- 2. the neutral particle in the nucleus
- 4. this type of radiation is all around us
- 7. process when an atom becomes a charged ion
- 8. this type of radiation is negatively charged
- 10. the time taken for half the radioactive atoms to decay
- 11. the positive particle in the nucleus
- 12. this radiation is used in radiotherapy
Down
- 1. units of activity of radioactive materials
- 3. the negative particle in an atom
- 5. these type of nuclei give out radiation
- 6. electrons do this around the nucleus
- 9. this radiation is stopped by paper