The Structure Of An Atom

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Across
  1. 6. the electrons are arranged in electron shells or orbits around the nucleus so what is this called?
  2. 7. which particle has no electrical charge?
  3. 8. who discovered the electron?
Down
  1. 1. how does first group known as?
  2. 2. where in the periodic table do you find metals?
  3. 3. there are three protons in lithium so what is the atomic number?
  4. 4. which of the three particles that make up the atom has the smallest mass?
  5. 5. which particles move around the nucleus?
  6. 9. which particle of an atom has a positive electrical charge?