Download Skinner Chapter 2

Fall 2000
Lohrengel
Geology 1013 - Earth System Science
Chapter 2 Questions - Study
Instructions:
Read each question carefully before answering. Work at a steady pace, and you should
have ample time to finish.
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1. The Sun is a star about 5 million years old.
2. The universe is at least twice and possibly three times as old as
the Sun.
3. The revolutions and rotations of the Sun, planets, and moons are
inherited from the rotation of the cosmic gas cloud from which the
solar nebula formed.
4. The four innermost planets are called terrestrial planets because
they all have the same chemical composition and density as the
Earth.
5. All of the planets farther from the Sun than Mars are much larger
than the terrestrial planets, and consist primarily of thick,
gaseous atmospheres.
6. The present distribution of the planets (inner, rock planets and
outer, icy planets) reflects the temperature and compositional
gradients within the solar nebula during the processes of
condensation and planetary accretion.
7. The bulk composition of Jupiter and Saturn is essentially the same
as that of the solar nebula from which they formed.
8. The Earth differs from the other terrestrial planets in that its
asthenosphere is unusually thick and buried deep within the planet.
9. The metallic cores of the terrestrial planets are all approximately
the same size.
10. The Earth is the only planet that has an asthenosphere.
11. Ancient astronomers believed that the entire Universe revolved
around the Earth. This is referred to as the _____________
astronomical system.
a. geocentric
b. heliocentric
c. egocentric
d. Copernican
12. The law of gravitation states that
a. what goes up must come down.
b. once a body is moving it will stop or change direction only in
response to another force.
c. every body in the universe attracts every other body.
d. all falling bodies, regardless of their mass, fall with uniform
acceleration.
13. The chemical composition of the Earth's crust is
a. about the same as that of the Sun.
b. about the same as that of the mantle.
c. typical of the overall composition of the Earth.
d. None of these is true.
14. Stars
a. generate heat and light through the process of nuclear fission in
their cores.
b. that are similar to our Sun formed in a huge cosmic cloud at the
time of formation of the universe.
c. consist predominantly of hydrogen and helium.
d. All of these are true.
15. Our solar system formed approximately
a. 15 billion years ago.
b. 4.6 billion years ago.
c. 3.9 billion years ago.
d. 4.0 billion years ago.
16. H 2O
a. only exists on the Earth.
b. exists on Mercury, but only in the form of water vapor in the
atmosphere because this planet is much hotter than the Earth.
c. exists on Mars but only in the form of ice, because Mars is too
cold for liquid water to be present.
d. is the third most abundant component of the Earth's atmosphere
(after nitrogen and oxygen).
17. The planets
a. formed from the same cloud of gas and dust as the Sun.
b. formed in different places in space and were drawn to the Sun by
gravity.
c. formed at the same time as the Sun.
d. were ejected from the Sun as molten matter early in its history.
18. The terrestrial planets, including the Moon, all have
a. crusts, mantles, and cores.
b. strong magnetic fields.
c. atmospheres.
d. asthenospheres that are close to the surface of the planet.
e. All of these are true.
19. The atmospheres of Jupiter and Saturn
a. are so thick that we have never been able to see or probe the
surfaces of these planets.
b. have changed substantially in composition since the formation of
the planets early in solar system history.
c. are composed primarily of heavy gases.
d. hide metallic cores, much like those of the terrestrial planets,
only bigger.
20. The crust of the Earth is
a. roughly the same as the mantle in overall composition and
density.
b. very variable in composition.
c. essentially the same as that of the other terrestrial planets, in
terms of overall composition, density, and thickness.
d. None of these is true.
21. Kepler recognized that the shape of the planetary orbits is
a. circular.
b. eccentric.
c. irregular.
d. elliptical.
22. The Earth's asthenosphere is
a. a hot, plastic, "weak" layer of rock.
b. just below the lithosphere.
c. part of the mantle.
d. All of these are true.
23. The only terrestrial planet that does not have an atmosphere is
a. Mars
b. Earth
c. Venus
d. Mercury
24. Mercury and the Moon lack atmospheres because they
a. never released gases from their interiors through volcanic
activity.
b. are too small.
c. are not dynamic planets like the Earth, Venus, and Mars.
d. All of these are true.
25. The differences between continental crust and oceanic crust on the
Earth
a. are part of the evidence that plate tectonics is an active
process on the Earth.
b. are similar to crustal differences observed on the other
terrestrial planets.
c. are part of the evidence that the Earth's core is more active
than that of the other terrestrial planets.
d. range up to 8 km in thickness from one place to another.
26. To date, no spacecraft have landed on
a. Venus.
b. Mercury.
c. Mars.
d. the Moon.
27. One of the outer planets is much smaller and less dense than the
others. It is
a. Neptune.
b. Uranus.
c. Saturn.
d. Pluto.
28. The terrestrial planet that has the largest core, relative to the
size of the planet itself, is
a. Mercury.
b. Venus.
c. Earth.
d. Mars.
29. There are seasons on Earth because the
a. Earth's orbit is circular rather than elliptical.
b. Earth's spin axis is tilted with respect to the plane of its
orbit around the Sun.
c. Earth spins with retrograde motion relative to the other planets
in the solar system.
d. All of these are true.
30. Which one of the following is not attributed to Johannes Kepler?
a. the law of ellipses
b. the law of equal areas
c. the law of gravitation
d. the law of orbital harmony
31. There are ____________ principal planets in our solar system.
32. The planets revolve around the Sun in _____________-shaped orbits.
33. All of the planets, with the exception of ____________, rotate
around their axes in the same counterclockwise direction as they are
revolving around the Sun.
34. The formation of the solar system occurred about _____________ years
ago.
35. The planetary bodies formed and grew in the solar nebula through a
process known as ________________.
36. At the center of each of the terrestrial planets is a core made
primarily of ________________.
37. The outer planets, with the exception of _______________, are
shrouded by thick atmospheres rich in hydrogen and helium.
38. The terrestrial planets are all characterized by an internal
structure consisting of three main layers: a(n) _________________,
a(n) _________________, and a(n) _________________.
39. The discovery of the law of gravitation is attributed to
___________________.
40. The Earth's lithosphere is made up of the ______________ part of the
crust and the ______________ part of the mantle.
41. Draw a diagram illustrating Kepler's law of equal areas.
42. What were the three laws of planetary motion discovered by Johannes
Kepler, and what does each one state?
43. What are the four terrestrial planets? Why are they called
"terrestrial"?
44. Why is it considered likely that a nearby supernova had something to
do with the solar system's formation?
45. How does the rotation of Venus differ from that of the other
planets?
46. How do scientists explain the rarity of CO 2 in the Earth's
atmosphere?
47. Make a neat, well- labelled diagram showing the internal structure
(as we know it) of the Moon. Compositional variations should be
noted.
48. In what states of matter is hydrogen thought to exist in Jupiter and
Saturn? Make a neat, well- labelled diagram showing the probable
interior structure of Jupiter.
49. Make a neat, well- labelled diagram showing the interior structure of
the Earth, including the layers of differing composition and rock
strength.
50. Why do the giant planets possess much more volatile and icy material
and mass than do the terrestrial planets?
51. The four key factors controlling the evolution of a planet are (1)
melting, (2) volcanism, (3) distance from the Sun, and (4) the
presence or absence of a biosphere. Discuss, using the terrestrial
planets for comparative purposes.
52. Our Sun is currently in a phase of its stellar evolution in which it
is producing helium from hydrogen present in its core. All other,
heavier elements can form only in the cores of stars more massive
than our Sun, or during the process of a supernova. If this is true,
then how is it possible that elements heavier than helium exist in
the Sun and in other parts of our solar system?
53. Why do you think it is important to begin a study of the Earth
system with a comparison of the Earth with other planets in our
solar system?
54. Briefly describe the processes of star formation and condensation of
material in the solar nebula.
55. Why are there layers of differing rock strength and different
physical state within the Earth?
56. Why is understanding a planet's interior helpful in understanding
its surface features and processes?
57. How might we go about determining whether a planet is (or has ever
been) geologically active in its interior?
58. Venus and Earth are about the same size and mass. Degassing
volcanoes on each probably discharged abundantly both CO 2 and H 2O
into their atmospheres. Why is CO 2 a major constituent of the
atmosphere only on Venus? Why is H 2O not a major constituent of the
atmosphere on either planet?
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Fall 2000
Lohrengel
Geology 1013 - Earth System Science
Answer Key: Chapter 2 Questions - Study
1. F
2. T
3. T
4. F
5. F
6. T
7. T
8. F
9. F
10. F
11. A
12. C
13. D
14. C
15. B
16. C
17. A
18. A
19. A
20. B
21. D
22. D
23. D
24. B
25. A
26. B
27. D
28. A
29. B
30. C
31. nine
32. elliptical
33. Venus
34. 4.6 billion
35. planetary accretion
36. (iron) OR (metal) OR (iron and nickel)
37. Pluto
38. core...mantle...crust
39. Sir Isaac Newton
40. lower...upper OR bottom...top
41. [See Fig. 2.6 in the text.]
42. (1) The law of ellipses: The orbit of each planet is an ellipse with
the Sun at one focus;
(2) The law of equal areas: A line drawn from a planet to the Sun
sweeps out equal areas in equal times;
(3) The law of orbital harmony: For any planet, the square of the
orbital period in years is proportional to the cube of the
planet's average distance from the Sun.
43. Mercury, Venus, Earth, Mars
They are called "terrestrial" because they are similar to the Earth,
in having relatively high overall densities, rocky compositions, and
differentiated (layered) internal structures.
44. A supernova is the most likely source for the heavy elements present
in the Sun and the rest of the solar system. [It is also possible
that a supernova may have created the shock wave that initiated
compression and collapse of the interstellar cloud of gas and
dust, leading to the formation of the solar nebula. This is not
covered in the text.]
45. The other planets rotate about their axes in the same sense in which
they revolve around the Sun (which is also the same direction as the
Sun's own rotation about its axis). Venus, in contrast, rotates in
the opposite direction about its axis (retrograde rotation), as
though it had been turned upside down.
46. On the Earth, plants and microorganisms have enabled carbon dioxide
and water to combine, through photosynthesis, to make organic matter
and oxygen. The burial of organic matter in sediment in effect
removes carbon dioxide from the atmosphere.
47. [See Fig. 2.15 in the text.]
48. [See Fig. 2.17 in the text.] In the atmospheres of Jupiter and
Saturn, hydrogen occurs as a gas, but deep inside the planets where
pressures are very great, hydrogen may exist in the form of
molecular and metallic liquids, and possibly even as solid metallic
hydrogen.
49. [See Fig. 2.14 in the text.]
50. The giant (or jovian) planets formed in the outer parts of the solar
nebula, where temperatures were very cold, and icy materials were
condensing. The terrestrial planets formed in the inner part of the
solar nebular, where temperatures were much higher, and more
refractory, denser rocky and metallic materials were condensing.
51. * not available *
52. * not available *
53. * not available *
54. * not available *
55. * not available *
56. * not available *
57. * not available *
58. * not available *