Across
- 2. wide spread occurrence in the Earth's crust
- 4. second most abundant element in the human body
- 7. the oldest known pills
- 9. one of the first mental to be used by humans
- 10. so dangerous the 19th century experimenter were deemed
- 12. table salt
- 13. found on the sun before earth
- 14. few elements that is liquid
- 16. it is the fifth most abundant chemical
Down
- 1. highest electrical conductivity
- 3. first metal to be worked by men
- 5. 24.305
- 6. main component of teeth and bones
- 8. First used a a weapon in world war 1
- 11. blood is red
- 15. formally used in self luminous paints for watches