1. The process by which rock breaks down into smaller pieces by physical change 2. the process by which natural forces break up rocks
3. Breakdown of the rock by chemical reactions that change the chemical composition of the rock
4. process in which layers of rock gradually break apart as pressure is released from the rock
5. the repeated freezing and thawing of water on rocks that causes the rock to split
6. Combining oxygen from air and water with iron from rocks to produce iron oxide (rust)
7. The sphere of the Earth which is a mass of liquid that is continuously in motion, evaporating from the oceans to the atmosphere, rushing towards the earth and returning to the ocean again.
8. The gaseous portion of a planet .
9. The totality of life on Earth .
10. The thin and rocky outer layer of the earth and is divided into oceanic and continental crust.