Across
- 2. process of conversation of dead vegetation into coal
- 3. the various components obtained during refining of petroleum
- 5. contains 40% carbon
- 6. chemicals derived from petroleum and natural gas
- 8. contains 90% carbon
- 9. hydrocarbon made up of carbon and hydrogen and has chemical formula of ch4
Down
- 1. Known as brown Coal
- 2. period when earth was covered with dense and swampy forests
- 4. also known as crude oil
- 7. resources which are constantly available regardless of use