lk

123456789
Across
  1. 3. A protective barrier made of lead that absorbs and blocks harmful radiation.
  2. 5. The total number of protons and neutrons found in the nucleus of an atom.
  3. 6. The natural process in which an unstable radioactive atom loses energy over time.
  4. 7. A positively charged subatomic particle located in the nucleus of an atom.
  5. 8. A negatively charged subatomic particle that moves around the nucleus of an atom.
  6. 9. A type of radiation that has enough energy to remove electrons from atoms and molecules.
Down
  1. 1. An instrument used to detect and measure levels of radioactive radiation.
  2. 2. The amount of time required for half of a radioactive substance to decay.
  3. 4. The emission of energy as waves or particles through space or matter.
  4. 7. A highly radioactive chemical element commonly used in nuclear reactors and nuclear weapons.