Across
- 3. many unstable materials breaking down into stable materials
- 5. over time, the solar nebula flattened in to this
- 6. resulted in a dense center and concentric layers around the core
- 8. as Earth formed, it became this
- 9. about 4.6 billion yrs ago, a cloud of gas & dust pulled together and rotated
- 10. when Earth was experiencing this, it allowed materials within the planet to move and flow
- 13. the star that is the center of our solar system
- 14. formed in the inner part of the disk from dense rocky & metallic materials
- 17. energy of motion
- 19. one of the gases that volcanoes belched out
- 21. one of the gases that volcanoes belched out
Down
- 1. when you lift an object off the ground, it gains this.
- 2. the force of this pulled high-density materials towards the center
- 4. this occurred as the planet cooled and solidified
- 7. this dense material began to sink toward the center due to the force of gravity
- 11. scientists think the universe formed these many billion years ago
- 12. center
- 15. continues to be generated in Earth's interior
- 16. continue to pour out molten rock
- 18. the largest bodies became these
- 20. one of the gases that volcanoes belched out