Across
- 2. floating balloons are filled with this
- 5. symbol is B and atomic number 5
- 9. is the lightest halogen
- 10. symbol is At
- 11. symbol is Ge and atomic number is 32
- 14. symbol is H
- 15. was discovered in 1811 by Bernard Courtois
- 16. atomic number is 30
- 18. discovered by Joseph Black in 1755
- 19. has an atomic weight of 114.818
Down
- 1. atomic number is 18
- 3. hydrargyrum
- 4. symbol is Br
- 6. atomic number is 116
- 7. it appears between fluorine and bromine in the periodic table
- 8. has an atomic weight of 6.94
- 10. has an atomic weight of 74.9216
- 12. salty
- 13. atomic number is 45
- 17. used glow lamps