Across
- 4. most penetrating for of radiation
- 6. when a substance has another mixed or disposed within it
- 7. number of counts from a sample per second
- 10. the time for the number of nuclei to reduce by half
- 12. centre of an atom
- 16. household appliance that uses radiation
- 17. the unit of which activity is measured in
- 18. the cause an atom to become charged by gaining or losing an electron
- 20. can penetrate paper but no aluminium
- 21. responsible for the nuclear model of the atom
- 22. group 0 elements
Down
- 1. sub-atomic particle with a positive charge
- 2. process of exposing an object to a source of radiation
- 3. the most ionising type of radiation
- 5. an element that is likely to react with another element
- 8. responsible for plum pudding model
- 9. sub-atomic particle with a negative charge
- 11. atoms of the same element with a different number of neutrons
- 13. what the electrons are on
- 14. sub atomic particle with no charge
- 15. alpha particle has what type of nucleus
- 19. the charge of an atom