Across
- 5. the 6th group
- 7. periods
- 9. made up with chemical elements with simular properties
- 11. found in nature combined with other elements
Down
- 1. family 5a
- 2. group 1a
- 3. designer of the periodic table
- 4. know as these in the 7th group
- 6. groups
- 8. group 2a
- 10. group 4a