Pretest

1. Rotation is the spinning motion of a body on its axis, while revolution is the elliptical motion of a body as it orbits another body.

2. An ellipse is the event in which the shadow of one celestial body falls on another, while a circle is a closed plane curve, consisting of all points at a given distance from a point within it which is the center.

3. The solar system is the system consisting of the sun, the planets, and the other bodies that travel around the sun, while the solar nebula is the nebula that formed the solar system.

4. A planetesimal is the tiny building blocks of the planets that formed as dust particles, stuck together, and grew in size, while a planet is a body revolving around a star rather than the sun.

5. Temperature is measure of how hot or cold something is, while pressure is the exertion of force upon a surface by something in contact with it.

6. A photosphere is the layer of the sun at which point the gases get thick enough to see; the surface of the sun, while the corona is the sun’s other atmosphere, which can extend outward a distance equal to 10-12 times the diameter of the sun.

7. It takes millions of years for light energy to travel through the suns radiative zone.

8. Rotation of the Earth causes night and day.

9. Convection in Earth’s mantle causes nuclear fusion.

10. A.

11. A.

12. B.

13. C.

14. B.

15. A.

16. C.

17. A.

18. The pressure and gravity are in balance. When two nubulas crash into each other the, balance is then off.