Atoms and the Periodic Table

12345678910
Across
  1. 2. The columns going down are called this.
  2. 4. The symbols and numbers which represent the atoms in a substance.
  3. 6. The reactivity of groups 1 and 2 _ _ _ _ _ _ _ _ down the group.
  4. 9. The elements in this group are more or less unreactive.
  5. 10. The periodic table is split into metals and what?
Down
  1. 1. An atom is the smallest possible part of an _ _ _ _ _ _ _ that exists.
  2. 3. The rows going across are called this.
  3. 5. All the known elements are arranged in this.
  4. 7. This is the surname of the chemist who created the periodic table.
  5. 8. More than one element chemically joined together is what?