Across
- 1. Positive charge in the nucleus
- 6. Most ionising power
- 8. Electrons are on these outside the nucleus
- 9. Unequal number of electrons to protons
- 10. What is on the outer shells of an atom
- 14. Spontaneous and Random
- 17. How far radiation can go into a material
- 18. Nucleus identical to an alpha particle
Down
- 2. Said electrons were outside nucleus
- 3. Designed plum pudding model
- 4. What holds the neutrons and protons in an atom
- 5. Time for activity to drop to half its value
- 7. Number of counts from a sample per second
- 11. No charge and in the nucleus
- 12. When an atom gains or loses electrons
- 13. Electromagnetic wave
- 15. Same number of protons, different number of neutrons
- 16. Particle with a relative charge of -1