science
Across
- 2. the number of protons
- 4. It has no charge
- 9. helium nucleus
- 10. positive charge
- 12. breaking up nucleus
- 13. how long it takes to reduce to half
- 14. heavy twin of atom
Down
- 1. protons plus neutrons
- 3. A neutron turns into a proton and electron is kicked out and the element changes
- 5. center of the atom
- 6. No charged particles released only high energy rays
- 7. radiation
- 8. atom bomb
- 11. combining of atoms