Across
- 4. I have a negative charge and move quickly
- 8. exposure to radiation
- 9. a radiation that doesn't penetrate
- 12. naturally occurring radioactive material and particles from space give rise to this form of radiation
- 13. too many or too few neutrons
Down
- 1. the time taken for the activity to decrease by a factor of 1/2
- 2. joining small nuclei, the source of energy in stars
- 3. nuclei broken apart in a controlled chain reaction to produce heat and energy
- 5. I contain radioactive atoms but shouldn't. I am ......
- 6. A massless form of ionising radiation
- 7. because of these errors in genetic code cells divide uncontrollably and cause cancer
- 10. 2 electrons, 2 protons and 2 neutrons
- 11. an atom will decay and give out radiation if it is ......