Extra Credit

6. A planet that lost mantle convection due to quick cooling caused by its smaller size.
10. The state where the San Andreas Fault is located.
11. I am a type of crust that is dark in color, thick, very dense, makes up ocean floor
14. Pieces of Earth's crust moved by mantle convection currents.
16. Convection works in ___ directions.
17. Earth's surface is broken into pieces called ____.
18. Ice floats in water because it's ____ is less than the water it is in.
19. The upward force allowing less dense materials to float above denser ones.
20. A boundary where tectonic plates crash into each other, often forming mountains or trenches.

1. When something expands because heat has caused particles in the substance to move faster.
2. A type of boundary where tectonic plates slide past one another horizontally.
3. A process that decreases the density of mantle material, making it rise.
4. I am a type of crust that is light in color, thick, less dense, makes up continents
5. The movement of heat by the circulation of material in Earth's mantle.
7. The process of one plate sinking below another.
8. Heat transferred by flowing matter.
9. A boundary where tectonic plates move away from each other due to mantle convection.
12. Thermal expansion causes a material to decrease in _____.
13. The semi-solid layer between the Earth's crust and core, where convection occurs.
15. If a planet loses ____, mantle convection stops.