Gives concentration of heavy elements toward centre. Use earthquakes to study discontinuities. Composition can be inferred from densities and discontinuities. Degassing gives hydrosphere and atmosphere. Earth's atmosphere is tertiary.
Biology now supplies much of the chemistry.
Goldsmith and Owen, ch. The duration will be one hour. There will be 6 questions, of which you need answer only 5. At least one of the questions will be similar to the non-quantitative ones at the ends of the chapters in the book, so it is a good idea to work those through and make sure you understand them. Please don't be shy.