AST Exam 3 Ch. 5,6,7.txt

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  1. Why did the solar nebula flatten into a disk?
    • It flattened as a natural consequence of collisions between particles in the nebula, changing
    • random motions into more orderly ones.
  2. When an electron in an atom goes from a higher energy state to a lower energy state the atom...
    emits a photon of a specific frequency.
  3. Which planet, other than the earth, has visible water ice on it?
  4. When light reflects off an object, what is the relation between the angle of incidence and the
    • angle of reflection?
    • angle of incidence = angle of reflection
  5. If a material is transparent, then it...
    transmits light well.
  6. Which of the following is furthest from the Sun?
    a comet in the Oort cloud
  7. From lowest energy to highest energy, which of the following correctly orders the different
    • categories of electromagnetic radiation?
    • radio, infrared, visible light, ultraviolet, X rays, gamma rays
  8. Under what circumstances can differentiation occur in a planet?
    The planet must have a molten interior.
  9. Which is the densest planet in the solar system?
  10. According to our theory of solar system formation, why do all the planets orbit the Sun in the
    same direction and in nearly the same plane?
  11. The laws of conservation of energy and conservation of angular momentum ensure that
    any rotating, collapsing cloud will end up as a spinning disk.
  12. Which of the following is not a characteristic of the inner planets?
    They all have substantial atmospheres. 2
  13. Why does the earth have the strongest magnetic field among the terrestrial worlds?
    • It is the only one that has both a partially molten metallic core and reasonably rapid
    • rotation.
  14. Which of the following worlds has the greatest difference in temperature between its "no
    • atmosphere" temperature and its actual temperature?
    • Venus
  15. How does the Sun's mass compare with that of the planets?
    It is a thousand times more massive than all the planets combined.
  16. Why does Venus have such a great difference in temperature between its "no atmosphere"
    • temperature and its actual temperature?
    • It has a large amount of greenhouse gases in its atmosphere.
  17. Why does Mercury have such a great change in temperature between its day and night?
    It has a slow rotation.
  18. From shortest to longest wavelength, which of the following correctly orders the different
    • categories of electromagnetic radiation?
    • gamma rays, X rays, ultraviolet, visible light, infrared, radio
  19. Which planet has the highest average surface temperature, and why?
    Venus, because of its dense carbon dioxide atmosphere
  20. How are wavelength, frequency, and energy related for photons of light?
    Longer wavelength means lower frequency and lower energy.
  21. When white light passes through a cool cloud of gas, we see
    an absorption line spectrum.
  22. Grass (that is healthy) looks green because
    it reflects green light and absorbs other colors.
  23. Which of the following is not a characteristic of the outer planets?
    They have very few, if any, satellites. 3
  24. Rank the five terrestrial worlds in order of size from smallest to largest:
    Moon, Mercury, Mars, Venus, Earth.
  25. The wavelength of a wave is
    the distance between two adjacent peaks of the wave.
  26. What percentage of the mass of the solar nebula consisted of elements other than hydrogen and
    • helium?
    • 2 percent
  27. Which of the following statements about X rays and radio waves is not true?
    Neither X rays nor radio waves can penetrate the earth's atmosphere.
  28. Heat escapes from the planet's surface into space by thermal radiation. Planets radiate almost
    • entirely in the wavelength range of the
    • infrared.
  29. Which describes convection?
    • It is the process in which warm material expands and rises while cool material contracts
    • and falls.
  30. We can learn a lot about the properties of a star by studying its spectrum. All of the following
    • statements are true except one. Which one?
    • The total amount of light in the spectrum tells us the star's radius.
  31. How does the greenhouse effect work?
    • Greenhouse gases transmit visible light, allowing it to heat the surface, but then absorb
    • infrared light from the earth, trapping the heat near the surface.
  32. How do asteroids differ from comets?
    Asteroids are rocky bodies and are denser than the comets, which are made of icy material.
  33. The planet closest in size to Earth is
    Venus. 4
  34. Why are the inner planets made of denser materials than the outer planets?
    • In the inner part of the nebula only metals and rocks were able to condense because of the
    • high temperatures, whereas hydrogen compounds, although more abundant, were only
    • able to condense in the cooler outer regions.
  35. Which of the following statements about X rays and radio waves is not true?
    X rays travel through space faster than radio waves.
  36. What percentage of the solar nebula's mass consisted of hydrogen and helium gases?
    98 percent
  37. Which of the following best describes Pluto in terms of the general characteristics of terrestrial
    • and jovian planets?
    • size and solid surface similar to terrestrial planets; distance and density similar to jovian
    • planets
  38. Where did the elements heavier than hydrogen and helium come from?
    They were produced inside stars.
  39. The lithosphere of a planet is the layer that consists of
    the rigid rocky material of the crust and uppermost portion of the mantle.
  40. What happened during the accretion phase of the early solar system?
    Particles grew by colliding and sticking together.
  41. Why did the solar nebula heat up as it collapsed?
    • As the cloud shrank, its gravitational potential energy was converted to kinetic energy and
    • then into thermal energy.
  42. According to the nebular theory, how did the Kuiper belt form?
    • It is made of planetesimals that formed beyond Neptune's orbit and never accreted to form 5
    • a planet.
  43. What are the main constituents of the jovian planets?
    hydrogen and helium
  44. What is differentiation in planetary geology?
    the process by which gravity separates materials according to density
  45. If we observe one edge of a planet to be redshifted and the opposite edge to be blueshifted, what
    • can we conclude about the planet?
    • The planet is rotating.
  46. What was the frost line of the solar system?
    • the distance from the Sun where temperatures were low enough for hydrogen compounds
    • to condense into ices, between the present-day orbits of Mars and Jupiter
  47. The most metal rich terrestrial planet is
  48. What are the circumstances under which convection can occur in a substance?
    when the substance is strongly heated from underneath 6
  49. If a material is highly opaque, then it ...
    absorbs most light.
  50. The terrestrial planet cores contain mostly metal because
    • metals sank to the center during a time when the interiors were molten throughout.
    • The core, mantle, and crust of a planet are defined by differences in their composition
  51. What are greenhouse gases?
    gases that absorb infrared light 78
Card Set:
AST Exam 3 Ch. 5,6,7.txt
2011-11-03 05:32:03
astronomy hayley howell

AST Exam 3 Ch. 5,6,7
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