crossword

12345678910
Across
  1. 2. Process in which a radioactive atom breaks down over time.
  2. 5. Lead barrier that protects against harmful radiation.
  3. 6. Radioactive element used in nuclear energy and weapons.
  4. 8. Negatively charged particle that moves around the nucleus.
  5. 9. Device used to detect and measure radiation.
  6. 10. Positively charged particle inside an atom’s nucleus.
Down
  1. 1. Energy that travels as waves or particles.
  2. 3. Total number of protons and neutrons in an atom.
  3. 4. Time needed for half of a radioactive substance to decay.
  4. 7. Radiation strong enough to remove electrons from atoms.