THe Atom

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Across
  1. 5. = the building blocks of matter
  2. 7. = scientist who is credited with discovering the electron
  3. 10. = equal in number to the number of protons
  4. 12. = helps scientist understand something that we cannot directly see
  5. 13. number = number of protons in an atom
  6. 14. = particle with the same mass as a proton
  7. 15. = name of element used in fluorescent signs
  8. 17. = Fe is the symbol
  9. 18. = negatively charged particle
  10. 20. = scientist credited with discovering the proton
  11. 21. = the maximum number of electrons the second energy can hold
  12. 22. = symbol for silver
Down
  1. 1. = scientist who discovered the neutron
  2. 2. = element with 78 protons
  3. 3. = scientist who developed the planetary model of the atom
  4. 4. = atom of an element with a different number of neutrons
  5. 5. mass = sum of the protons and neutrons
  6. 6. = element often made into electrical wire
  7. 8. = only atom with atoms which do not have neutrons
  8. 9. = element that has 9 electrons
  9. 10. cloud = region surrounding the nucleus which is occupied by electrons
  10. 11. = name of element whose symbol is Ru
  11. 14. = symbol for sodium
  12. 16. = center of the atom
  13. 19. = positively charged particle in the nucleus