Across
- 1. environmental problem linked to rising CO2 levels in the atmosphere
- 5. substance which releases energy
- 6. contributes to acid rain
- 8. effect of catalyst on rate of reaction
- 9. gas needed for combustion
- 10. periodic table version 1
- 11. gases family of unsociable elements
Down
- 1. carbon dioxide and water are examples
- 2. substance with the formula CaSO4
- 3. Gaseous element which exists as diatomic molecules
- 4. crude oil is separated into fractions based on
- 7. The periodic table is a table of