Across
- 7. The most ionising, least penetrating radiation
- 9. J.J. Thomson's model of the atom
- 12. Neutrally charged particle with a relative mass of 1
- 13. Negatively charged particle that orbits nucleus
- 14. Version of an atom with more or less neutrons that normal
- 15. When a large unstable particle gives off radiation
Down
- 1. The least ionising, most penetrating radiation
- 2. Fire safety device that uses alpha radiation to work
- 3. Positively charged particle found in the nucleus
- 4. Medical technique used to treat brain tumors
- 5. Serious disease that can be caused by radiation
- 6. The time taken for half of a substance to decay
- 8. His experiment proved that the nucleus exists
- 10. Radiation give off when a neutron decays into a proton
- 11. Something that could fall apart at any moment
- 14. Atom that has gained or lost electrons