Across
- 2. Basis of life's organic molecules.
- 6. 1% of the air, inert gas.
- 9. Inert gas in lasers and tubes for advertising signs
- 10. Radioactive, long-lived, and dense element in nuclear weapons.
- 12. Hard metal in batteries, plows, axes, hard, tough steel.
- 13. Lightweight, non-corroding metal used in kitchenware, foil, and bikes.
- 15. Conducts electricity best of all elements. Used in jewelery.
- 17. Hard metalloid in quartz, granite, sand, soil, clay, and glass.
- 19. Dense, soft, non-corroding, toxic, metal in weights, and old plumbing.
- 20. Magnetic, medium-hard metal, magnets are made of this.
Down
- 1. Inert gas in lamps, projectors, and spacecraft ion engines.
- 3. Colorless gas we breathe
- 4. Soft metal, absorbs X-rays.
- 5. Hard, black solid, in sports equipment, and is in heat-resistant glass.
- 7. Colorless gas in 78% of the air
- 8. Lightest element
- 11. Toxic, liquid metal.
- 14. Lightest metal.
- 16. Soft metal, reactive, in salt, baking soda, and soap.
- 18. Disinfectant for wounds and drinking water.