Atoms and Elements- dee makwana

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Across
  1. 4. Who came up with periodic law?
  2. 6. Pb is the symbol for which element?
  3. 7. Negatively-charged particle.
  4. 10. Element with the lowest atomic number.
  5. 11. Ru is the symbol for which element?
  6. 12. K is the symbol for which element?
  7. 16. Electrons on the outermost energy level of an atom.
  8. 18. Atoms with the same number of protons but a different number of neutrons.
  9. 20. Group 17 on the periodic table.
Down
  1. 1. As you move from left to right on the periodic table, atoms become less __________ in their properties.
  2. 2. Chemical symbol for Neon.
  3. 3. An energy level representing the distance of an electron from the nucleus of an atom.
  4. 5. Particles with no charge.
  5. 8. A horizontal row of elements on the periodic table.
  6. 9. The sum of protons and neutrons in an element.
  7. 13. Negatively charged, results from gaining electrons.
  8. 14. The isotope that forms when "C" gains 2 neutrons.
  9. 15. In the modern periodic table, elements are arranged according to their ________________.
  10. 17. Straddle the boundary between metals and nonmetals; have properties of both.
  11. 19. Positively charged, results from losing electrons.