ASTR Ch. 8

According to radiometric dating of material in the solar system, how old is the solar system? A. about 4 and a half billion years old B. about 4 and a half million years old C. about 4 and a half trillion years old

A. about 4 and a half billion years old

Jovian planets contain much more helium than terrestrial planets do because A. as the Jovian planets were growing, they became massive enough for gravity to pull in neighboring gas, including the helium atoms in that gas B. the Sun's gravity pulled the heavier elements into the inner solar system but left the lighter elements in the outer solar system. The Jovian planets were formed in the outer part of the solar system and so had more helium to draw from than the terrestrial planets did C. in the region where these planets formed, it was cold enough for helium to condense into seeds, which then accumulated to form planetesimals. These helium-rich planetesimals plus planetesimals that contained other elements came together to form the Jovian planets. D. as the solar nebula's disk began to spin faster, it flung the helium out to the outer part of the solar system. The Jovian planets were formed in the outer part of the solar system and so had more helium to draw from than the terrestrial planets did

A. as the Jovian planets were growing, they became massive enough for gravity to pull in neighboring gas, including the helium atoms in that gas

The types of clouds that eventually form stars and planets rotate imperceptibly slow. But the planets in our solar system and other planetary systems orbit fairly quickly. Which of the following best explains why the rate at which material orbits the center of their planetary system increased over time? A. conservation of angular momentum B. conservation of energy C. the diffraction limit D. the Doppler effect E. newton's universal law of gravitation F. synchronous rotation G. tidal friction

A. conservation of angular momentum

How was the solar system affected by the solar wind and radiation emitted by the Sun when it was very young? A. even after the planets, moons, asteroids, and comets formed, there was still quite a lot of gas in the solar nebula. The Sun developed, blew a strong wind, and emitted photons that blew most of the leftover gas out of the solar system B. when all of the planets were very young, they had thick layers of hydrogen gas, just as the Jovian planets do today. However, during the early history of the solar system, the Sun's wind and radiation ignited the hydrogen gas layers of Mercury, Venus, Earth and Mars and burnt them up C. both of the above D. none of the aboave

A. even after the planets, moons, asteroids, and comets formed, there was still quite a lot of gas in the solar nebula. The Sun developed, blew a strong wind, and emitted photons that blew most of the leftover gas out of the solar system

Potassium-40 decays into Argon-40. The half-life for this decay is 1.25 billion years. That means that if you started with a 1 kilogram chunk of Potassium-40 and waited 1.25 billion years, A. you would now have 1/2 kilogram of Potassium-40 plus 1/2 kilogram of Argon-40 B. you would now have only 1 kilogram of Argon-40 C. you would now have only 1/2 kilogram of Potassium-40 D. you would now have only 1/2 kilogram of Argon-40

A. you would now have 1/2 kilogram of Potassium-40 plus 1/2 kilogram of Argon-40

The types of clouds that eventually form stars and planets are cold, far colder than the air around you. But, the terrestrial planets began to form in a region that was hot. Which of the following best explains why the temperature rose in the timespan between those two stages? A. conservation of angular momentum B. conservation of energy C. the diffraction limit D. the Doppler effect E. newton's universal law of gravitation F. synchronous rotation G. tidal friction

B. conservation of energy

What caused the craters on the Moon? A. when the Moon was young and somewhat molten, gas rose to its surface. The craters are the sites where gas bubbles broke open B. planetesimals collided with the Moon and the craters are the sites of such impacts C. planetesimals tend to be hollow shells. The moon formed from many planetesimals, but some had been broken open. The moon's craters are the hollow insides of some of the planetesimals that came together to make the moon D. none of the above

B. planetesimals collided with the Moon and the craters are the sites of such impacts

Which one if the following options was most important in enabling the Jovian planets to become more massive than the terrestrial planets (hint, it is possible that some of the following "facts" are not true) A. the fact that metals could condense in the regions where the Jovian planets were formed B. the fact that ices could condense in the regions where the Jovian planets were formed C. the fact that hydrogen and helium could condense in the regions where the Jovian planets were formed D. the fact that rocks could condense in the regions where the Jovian planets were formed

B. the fact that ices could condense in the regions where the Jovian planets were formed

Before the Sun was formed, the solar nebula contained some non-hydrogen, non-helium, non-lithium materials such as oxygen, silicon, and iron atoms. These elements are considered to be "heavy elements" in astronomy. Where did these "heavy element" atoms come from? A. very early in our solar system's history, they were made by nuclear fusion on the surfaces of the terrestrial planets B. they were produced by other stars in our galaxy before the Sun was born C. they formed within the Universe's first few minutes from materials created during the Big Bang D. they formed from ultraheavy atoms in interstellar space, when those atoms split into multiple smaller atoms

B. they were produced by other stars in our galaxy before the Sun was born

EXTRA CREDIT: Consider the radioactive decay of Potassium-40 into Argon-40, which has a half life of 1.25 billion years. (Make the simplifying approximations that the text implicitly made that this is the only possible way for Potassium to decay, that Argon does not decay, and that you won't acquire Potassium-40 as a result of any other element decaying. Therefore, you can use the equations and figures in the text.) When planetesimals were formed, they didn't have any Argon-40 in them. Suppose that we could measure the Potassium-40 and Argon-40 in a planetesimal in another solar system. Your measurements show that the planetesimal has 3 times as much Argon-40 as Potassium-40. How old is that planetesimal? ................. Hints: The original amount of Potassium-40 is the sum of the current amount of Potassium-40 plus the current amount of Argon-40. From the ratio of the current amount of Potassium-40 over the original amount of Potassium-40 you can determine the age using either Figure 8.14 or the equations in Mathematical Insight 8.1 or both. A. 0.625 billion years B. 1.25 billion years C. 2.5 billion years D. 3.75 billion years E. 5 billion years

C. 2.5 billion years

Where did the asteroids in the solar system come from? A. Before the solar nebula developed, the material that would become the solar nebula already contained asteroids. The asteroids that we have in our solar system now are simply the ones that survived the various processes that occurred in the solar system's early history. B. When the solar nebula formed, it contained trillions of dense regions, where the density of the gas was greater than in the regions between these dense spots. Each of the dense regions had enough gravitational attraction to cause its atoms to fall into the center of the region. Each of these dense regions became an asteroid. C. In the solar nebula, atoms in the gas gently collided and stuck together to make small seeds. These seeds combined with other seeds, and so on. In the regions where Mercury, Venus, Earth, and Mars are now, the combination of many such seeds resulted in asteroids. D. All of the asteroids in the solar system were formed when terrestrial planets and/or moons collided and broke up.

C. In the solar nebula, atoms in the gas gently collided and stuck together to make small seeds. These seeds combined with other seeds, and so on. In the regions where Mercury, Venus, Earth, and Mars are now, the combination of many such seeds resulted in asteroids.

Where were our solar system's icy planetesimals originally formed? A. between the Sun and the "frost line", which is located between the current orbits of Jupiter and Mars B. beyond the current orbit of Neptune C. beyond the "frost line", which is located between the current orbits of Jupiter and Mars D. throughout the solar nebula disk E. in the interstellar space outside of the solar nebula

C. beyond the "frost line", which is located between the current orbits of Jupiter and Mars

According to the theory that explains how the solar system formed, what happened to the solar nebula as it shrank in size? A. it turned inside out so that the material that had previously been on the edge of the cloud moved to the center where it formed the Sun B. it collapsed into a column-shaped bar C. it flattened into a disk D. it broke up into multiple concentric 3-dimensional shells or balls E. all of the above

C. it flattened into a disk

Regarding the comets in our solar system: A. the comets in our solar system are left-over rocky-metally planetesimals B. the comets in our solar system are left-over hydrogen-helium planetesimals C. the comets in our solar system are left-over icy planetesimals D. all of the above

C. the comets in our solar system are left-over icy planetesimals

Regarding moons: A. most of the large moons around the Jovian planets were formed by condensation and accretion of material around its host planet B. most of the small moons around the Jovian planets are captured asteroids or comets C. Earth's moon was made from material that had been blasted off when a planet-sized planetesimal collided with the Earth D. all of the above

D. all of the above

The solar system was formed from a nebula that was 98%: A. hydrogen compounds such as water, methane, and ammonia B. metals such as iron C. rocky material composed of elements such as silicon D. hydrogen and helium

D. hydrogen and helium

The planets in the solar system contain various materials, materials that they got from the solar nebula. Put these types of material in order from most plentiful to least plentiful in the solar nebula: A. metals (for examples: iron, nickel, aluminum) were more plentiful than hydrogen compounds (examples: water, methane, ammonia), which were more plentiful than rocky materials (for example: silicon) B. hydrogen compounds (examples: water, methane, ammonia) were more plentiful than metals (for examples: iron, nickel, aluminum), which were more plentiful than rocky materials (for example: silicon) C. rocky materials (for example: silicon) were more plentiful than hydrogen compounds (examples: water, methane, ammonia), which were more plentiful than metals (for examples: iron, nickel, aluminum) D. metals (for examples: iron, nickel, aluminum) were more plentiful than rocky materials (for example: silicon), which were more plentiful than hydrogen compounds (examples: water, methane, ammonia) E. hydrogen compounds (examples: water, methane, ammonia) were more plentiful than rocky materials (for example: silicon), which were more plentiful than metals (for examples: iron, nickel, aluminum) F. rocky materials (for example: silicon) were more plentiful than metals (for examples: iron, nickel, aluminum), which were more plentiful than hydrogen compounds (examples: water, methane, ammonia)

E. hydrogen compounds (examples: water, methane, ammonia) were more plentiful than rocky materials (for example: silicon), which were more plentiful than metals (for examples: iron, nickel, aluminum)

Which aspect of the nebular hypothesis is inconsistent with the actual behavior or the solar system? A. the tendency for the hydrogen-rich planets to be further from the sun than the terrestrial planets B. the tendency for all of the planets to orbit in the same direction C. the existence of comets D. the existence of asteroids E. all of the above F. none of the above

F. none of the above