Across
- 3. when metal is mixed with moisture and oxygen it forms ....?
- 6. the gas that comes from cars,starts with c
- 7. a chemical reaction that gives of heat
- 9. 78% of the air
- 11. a hemical reaction that reduces the heat of a substance
- 15. two or more substances mixed together to form one substance
- 16. the symbal o stands for ......?
Down
- 1. a way to stop rusting
- 2. gases that form a blanket around the earth heating it up
- 4. the three things needed to make a fire
- 5. The samllest particle in an element is called an ....?
- 8. a postively or negativly charged particle
- 10. limestone is a ........?
- 12. Ca,Re,V are all what?
- 13. two or more atoms chemically joined
- 14. another word for burning