Across
- 3. the brittle, rocky outer layer of Earth.
- 4. the dense metallic center of Earth.
- 7. the circular motion of fluids caused by differences in temperature and density.
- 8. Earth's outermost layer that lies beneath the oceans.
- 9. middle layer of Earth's atmosphere that acts like a protective shield.
Down
- 1. the cold and rigid outermost rock layer.
- 2. an invisible "shield" that extends from the planet's core out into space, protecting Earth from harmful solar radiation.
- 3. the thick, rocky layer of Earth's crust that forms the continents.
- 5. the plastic layer within the mantle.
- 6. the thick middle layer in the solid part of Earth.