Chapter 7 & 8

4. Every chemical element is made up of this.
5. Single continuous land mass that includes Asia and Europe.
7. An imaginary line about which the earth rotates.
9. This is why stars shine.
11. Continent of the south pole.
12. Bordered by the Indian Ocean to the East, and Atlantic to the west.
15. Iron sunk to the middle of the planet and the lighter formed crust.
18. The expanse of salt water that covers most of the earth's surface and surrounds its landmasses.
19. When will the sin engulf the inner planets (as a red giant)?
20. Cover about 1/10 of the Earth.
22. The smallest ocean.
24. Measured the speed of their ship by using a device called a "common log."
26. includes all the countries south of the panama border.
28. 5.5% is covered by ice.
29. Smallest continent in size.
30. Cloud of dust and gas within a galaxy.

1. The release of volatile substances and water vapor.
2. Said how the stars and planets formed.
3. This was not on Earth when it was formed.
6. The second largest ocean and is between Africa and North/South America.
8. includes U.S., Mexico, and Canada.
10. Huge rotating aggregations of stars, planets, and gas held together by gravity.
13. The theory that the universe is still expanding.
14. Forms in a nebula.
16. When a star starts to swell up and consume planets.
17. Occurred 15 billion years ago.
21. 4.5% is covered by ice.
23. The warmest ocean and a trade route between Asia and India.
25. When a star explodes.
27. How planets were formed.