Unit 2

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Across
  1. 2. What emits helium nuclei?
  2. 5. Which subatomic particle has a neutral charge?
  3. 7. An ion with a positive charge
  4. 8. What is the p orbital called?
  5. 11. What subatomic particle is massless?
  6. 12. Who had the plum pudding model?
  7. 15. Who arranged the periodic table in order of increasing atomic mass?
  8. 17. The total number of protons and neutrons in the nucleus of an atom
  9. 20. A region of space in which there is a high probability of finding an electron?
Down
  1. 1. The attractive force that holds the nucleus together
  2. 3. What borders the stair-step line between metals and nonmetals?
  3. 4. What did Goldstein discover?
  4. 6. A wave's height from zero to crest
  5. 9. The way electrons are arranged in various orbitals around the nucleus of an atom
  6. 10. Who used the scientific method to revise Democritus's model?
  7. 13. Who arranged the periodic table in order of increasing atomic number?
  8. 14. Who proposed that atoms were indestructible and indivisible?
  9. 16. Characterized by the presence of electrons in d orbitals
  10. 18. Who discovered the neutron?
  11. 19. What is the most electronegative element on the periodic table?