1. Chapter 9

2. 1. Our solar system most likely formed from a(n):
A. asteroid.
B. black hole.
C. nebula.
D. galaxy.

3. 2. Nebulae are composed mostly of:
A. carbon and oxygen.
B. nickel and iron.
C. hydrogen and helium.
D. silicon and aluminum.
E. silicon and oxygen.

4. 3. Stars are composed mostly of:
A. carbon and oxygen.
B. nickel and iron.
C. hydrogen and helium.
D. silicon and aluminum.
E. silicon and oxygen.

5. 4. Which of the following does not support the Nebular Hypothesis?
A. All of the planets orbit the Sun in the same direction.
B. All of the planets orbit the Sun in approximately the same plane.
C. The outer planets are enriched in volatile elements compared to the inner planets.
D. Earth is density stratified into a crust, mantle, and core.
E. All of these support the Nebular Hypothesis.

6. 5. The inner planets are composed primarily of:
A. hydrogen and helium.
B. ammonia and methane.
C. silicates, iron, and nickel.
D. ice.

7. 6. The outer planets are composed primarily of:
A. hydrogen and helium.
B. ammonia and methane.
C. silicates, iron, and nickel.
D. ice.

8. 7. Where in our solar system is there an asteroid belt?
A. between Earth and the Sun
B. between each planet
C. between the inner and outer planets
D. between Earth and Mars
E. beyond Pluto

9. 8. Which list places the four inner planets in order of increasing distance from the Sun?
A. Earth, Mars, Venus, Mercury
B. Mars, Mercury, Earth, Venus
C. Venus, Mercury, Earth, Mars
D. Mercury, Mars, Venus, Earth
E. Mercury, Venus, Earth, Mars

10. 9. Which list places the four outer planets in order of increasing distance from the Sun?
A. Neptune, Uranus, Saturn, Jupiter
B. Saturn, Jupiter, Neptune, Uranus
C. Jupiter, Saturn, Uranus, Neptune
D. Jupiter, Uranus, Saturn, Neptune
E. Saturn, Jupiter, Uranus, Neptune

11. 10. How old is the Moon compared to Earth?
A. about 50 million years younger
B. about 50 million years older
C. about 500 million years younger
D. about 500 million years older
E. They are the same age.

12. 11. Current evidence indicates that the Moon was produced by:
A. simultaneous accretion.
B. the eruption of magma into space.
C. Earth capturing an asteroid.
D. the collision of a Mars-sized body with Earth.

13. 12. The three compositional layers of Earth, from the surface to the center, are:
A. core, mantle, crust.
B. mantle, crust, core.
C. lithosphere, mantle, core.
D. crust, mantle, core.
E. lithosphere, asthenosphere, core.

14. 13. In comparison to continental crust, oceanic crust contains more
13. In comparison to continental crust, oceanic crust contains more and has a(n) density.
A. silicon; lower
B. iron; higher
C. silicon; higher
D. iron; lower
E. carbon; equal

15. 14. Earth’s core is composed primarily of __.
A. silicon and oxygen
B. hydrogen and helium
C. aluminum and potassium
D. gold and silver
E. iron and nickel

16. 15. The gases in Earth’s atmosphere came from:
A. space.
B. the oceans.
C. Earth’s mantle.
D. Earth’s core.

17. 16. Earth’s original atmosphere was mostly:
A. hydrogen, oxygen, nitrogen, water vapor.
B. hydrogen, carbon dioxide, nitrogen, helium.
C. hydrogen, carbon dioxide, oxygen, nitrogen.
D. hydrogen, carbon dioxide, nitrogen, water vapor.
E. oxygen, carbon dioxide, nitrogen, water vapor.

18. 17. Why does Earth appear to have fewer craters compared to other planets in the solar system?
A. Earth is younger than the other planets.
B. Earth’s processes destroy evidence of craters.
C. The inner planets are not hit by meteorites as often.
D. The Moon shields Earth from all impactors.

19. 18. Which of the following is not a true observation used to support the hypothesis that water once existed on the surface of Mars?
A. presence of stream channels
B. deposition of sulfate minerals
C. discovery of permafrost soils
D. fossil evidence of aquatic life
E. evidence of glacier activity

20. A. Mars B. Venus C. Jupiter D. Neptune E. Mercury
19. Which planet, other than Earth, has evidence of current tectonic activity?
A. Mars
B. Venus
C. Jupiter
D. Neptune
E. Mercury

21. 20. Approximately how many planets outside of our solar system are known?
B. 30
C. 300
D. 3000