Unit 4 vocab

2. waves Vibrations that move through Earth during an earthquake.
6. effect When gases in the atmosphere trap heat and keep Earth warm.
7. When one tectonic plate slides under another into the mantle.
9. tectonics The theory that Earth’s outer shell is divided into plates that move around.
10. spheroid A shape like Earth—round but slightly flattened at the top and bottom.
12. A supercontinent that existed long ago when all the continents were joined together.
14. decay When unstable atoms break down and release energy.
16. The layer of gases surrounding Earth.

1. The fastest earthquake waves that move through solids and liquids.
3. The thick layer of hot rock between Earth’s crust and core.
4. The movement of heat through liquids or gases as warm parts rise and cool parts sink.
5. When Earth’s crust cracks and pulls apart.
7. Slower earthquake waves that move only through solids.
8. The process plants use to make food using sunlight, water, and carbon dioxide.
11. Bright, colorful lights in the sky caused by particles from the sun hitting Earth’s atmosphere.
13. Effect The way Earth’s rotation makes moving air and water curve instead of going straight.
15. How much mass something has in a certain amount of space.