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