Periodic Table Puzzle

1234567891011121314151617181920
Across
  1. 2. Located on the left side of the periodic table
  2. 6. Group 1
  3. 7. Has atomic number of 82
  4. 8. Found by the formula atomic mass - atomic number
  5. 10. State of matter when a gas condenses
  6. 11. Elements in the same group have the same amount of ______
  7. 14. Found in toothpaste
  8. 17. The smallest particle of an element that retains all of the properties of an element
  9. 18. Trait group 1 has in common
  10. 20. What you do to a wrinkled shirt
Down
  1. 1. Known as the father of the periodic table
  2. 3. Lowly reactive metals that are good conductors
  3. 4. What state of matter are the particles closest together
  4. 5. Which group has two valence electrons
  5. 9. Least reactive family
  6. 12. The atomic number of an atom is the number of ________ in the atoms nucleus
  7. 13. What are the horizontal rows of the periodic table called
  8. 15. Another word for group
  9. 16. Properties are intermediate between those of metals and solid nonmetals or semiconductors
  10. 19. How many periods are there