Radiation

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Across
  1. 3. The time it takes a radioactive material to decay to half the original amount.
  2. 5. The nucleus of a helium atom ejected during radioactivity stopped by a piece of paper.
  3. 6. A particle like an electron, but with positive charge.
  4. 7. High-energy particle with no charge goes through lead but is stopped by water or concrete.
  5. 9. High-speed, high-energy electrons or positrons emitted from the nucleus stopped by thin wood or metal plates.
  6. 10. An element with a radioactive isotope essential for the human body and contained in many foods.
Down
  1. 1. The international unit measuring the radiation effect on the human body equivalent to 100 REMs.
  2. 2. A radioactive element contained in Earth’s soils.
  3. 4. One of the more radioactive fruits providing 0.1 microSieverts of radiation from the isotope Potassium-40.
  4. 8. Penetrating high-energy, photons emitted during radioactivity best stopped by thick metal plates.