Across
- 3. A radioactive noble gas that can accumulate in basements.
- 4. A reddish brown metal used in electrical wiring and coins.
- 5. The lightest metal, used in rechargeable batteries.
- 6. A precious metal with the highest electrical conductivity.
- 10. A noble gas used in bright colored advertising signs.
- 11. A transition metal that rusts when exposed to oxygen and water.
- 13. A gas necessary for human respiration and combustion.
- 14. The element essential to life; found in diamonds and graphite.
- 15. A noble gas used in balloons because it is lighter than air.
Down
- 1. A lightweight metal that burns with a bright white flame.
- 2. A greenish yellow gas used in disinfecting water.
- 7. A halogen needed in the diet to maintain a healthy thyroid.
- 8. A metalloid found in borax and used in making glass.
- 9. A radioactive metal used as fuel in nuclear reactors.
- 12. The lightest element and the most abundant in the universe.