Across
- 2. unstable nucli release radiation,losing energy
- 8. the amt of protons in an atom
- 11. radiation that is positively charged; directed btw 2 charged plates
- 12. avg mass of isotopes of the element
- 13. particles that leave radioactive materials
- 14. represents sum of protons and neutrons
- 15. some things give off radiation
Down
- 1. mass 1/12 of carbon 12 atom
- 3. stream of electrons
- 4. the building block of everything
- 5. same atoms different amts of neutrons
- 6. result of changes in an atoms nucleus
- 7. smaller atom w a positive charge of 1+
- 9. mass almost equal to a proton
- 10. negative particle;moves around nucleus