Radioactivity

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Across
  1. 1. Number of decays per second
  2. 5. Number of protons in a nucleus
  3. 6. Time for half the atoms to decay
  4. 7. Protons and neutrons found here
  5. 8. Charge on atoms
  6. 10. High energy electromagnetic radiation
  7. 12. particle with positive charge
  8. 13. Total number of protons and neutrons
Down
  1. 2. Atoms each with same number of protons
  2. 3. Negative particle
  3. 4. Natural radiation in the environment
  4. 6. Gas with one proton in nucleus
  5. 9. Particles with two protons + two neutrons
  6. 11. Atom with lost electron