Atoms and Periodic Table

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Across
  1. 2. an arrangement of elements
  2. 5. vertical columns in the periodic table
  3. 7. a particle with a positive or negative charge
  4. 8. group of atoms held together by chemical bonds
  5. 9. poor conductors of heat and electricity
  6. 12. horizontal rows in the periodic table
  7. 15. interaction that holds atoms or ions together
  8. 17. what is the mass number of an isotope of an atom with 2 neutrons and 1 proton
  9. 18. center of the atom
  10. 20. number the number of protons in the nucleus
  11. 21. a force that brings oppositely charged ions together
  12. 22. area that consists of electrons
  13. 23. has no charge
  14. 25. smallest particle an element can be divided into
Down
  1. 1. electrons found in the outermost level
  2. 3. what separates the metals from nonmetals on the periodic table
  3. 4. has a negative charge
  4. 6. what is the atomic number of a sodium atom that has 11 protons and 12 neutrons
  5. 8. number the total number of protons and neutrons in an atom
  6. 10. the total amount of electrons the first energy level can hold
  7. 11. atoms that share one or more pairs of electrons
  8. 12. has a positive charge
  9. 13. the total amount of electrons the second energy level can hold
  10. 14. elements that have properties of both metals and nonmetals
  11. 16. bonds between metal atoms when their outermost energy levels overlap
  12. 19. abbreviation for an element
  13. 24. elements that are shiny and conduct heat well