Marcus's crossword puzzle

123456789
Across
  1. 4. pure substance that consists entirely of one type of atom.
  2. 5. the number of protons in the nucleus of an atom element.
  3. 7. the total number of neutrons and protons in a atoms nucleus.
  4. 8. found a long the staircase have properties of both metals
  5. 9. brittle, dull,conductors of heat,and on right side of table.
Down
  1. 1. Group 1 most reactive metals on table.
  2. 2. horizontal rows on the periodic table.
  3. 3. positively charged particle in the nucleus.
  4. 4. a tiny, negatively charged particle that move around nucleus of atom.
  5. 6. a subatomic particle that is a neutral and found in the nucleus.