Matter and the Periodic Table Puzzle

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Across
  1. 3. I can be either heterogeneous or homogeneous.
  2. 5. Elemental symbol for tin.
  3. 6. My atomic number is 7.
  4. 7. I am a transition metal with 47 electrons used to make photographic film.
  5. 8. Substance that contains more than one element.
  6. 9. A combination of two or more atoms held together in a specific shape by attractive forces.
  7. 14. Electrons furthest from the nucleus that are responsible for interactions of atoms with one another also referred to as _________ electrons.
  8. 15. Arsenic is an example of this type of element.
  9. 17. I am one of the noble gases.
  10. 18. These types of elements are malleable, ductile and conduct electricity.
  11. 22. My atomic mass is 63.546 amu.
  12. 23. Members of Group 17 (or VIIA) are called _______.
  13. 24. Another name for a row of the periodic table.
  14. 25. Another name for a column of the periodic table.
Down
  1. 1. Protons, neutrons and electrons are classified as ________ particles.
  2. 2. Two forms of the same element that contain same number of protons but different number of neutrons.
  3. 4. An atom that has gained or lost one or more electrons.
  4. 5. If phosphorus gains 1 proton it turns into this element.
  5. 6. I am the positively charged center of an atom.
  6. 10. I am negatively charged and barely contribute to the mass of the atom.
  7. 11. I have no charge and you can find me at the center of an atom.
  8. 12. The number of _______ gives the identity of an element.
  9. 13. I have definite shape and volume.
  10. 16. I take the shape of the container I am in.
  11. 19. I am made up of hydrogen and oxygen atoms and you need me to live.
  12. 20. You can find me in Group 1 of the periodic table and in table salt.
  13. 21. I am the heaviest alkaline earth metal.