Plate tectonics

2. linear feature that exists between two tectonic plates that are moving away from each other.
6. a substance consisting of two or more substances mixed together
8. where Earth's tectonic plates dive back into the mantle,
10. core about 1300 miles (2092 km) thick.
12. the usual process at work at divergent plate boundaries, leading to the creation of new ocean floor
14. When two plates come together
15. planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements.
17. a layer inside a planetary body bounded below by a core and above by a crust
18. lies between the thermosphere and the stratosphere
19. zone of Earth's mantle lying beneath the lithosphere and believed to be much hotter and more fluid than the lithosphere.
20. a hot, dense ball of (mostly) iron

1. very hot, very dense center of our planet.
3. plates gigantic pieces of the Earth's crust and uppermost mantle.
4. application of balanced inward forces
5. most associated with the scientist Alfred Wegener
7. physical properties that a material exhibits upon the application of forces
9. Plate tectonics is the scientific theory that Earth's lithosphere comprises a number of large tectonic plates, which have been slowly moving since about 3.4 billion years ago.
11. places where plates slide sideways past each other
13. the outermost shell of a terrestrial planet.
16. the rigid outer part of the earth, consisting of the crust and upper mantle.