Quiz 5: Chapter 19, 20

Quiz 5: Chapter 19, 20

Multiple Choice

Identify the letter of the choice that best completes the statement or answers the question.

1. The oldest rocks found on Earth are about ____________ years old.

a.	10 billion
b.	5.3 billion
c.	2.6 billion
d.	4.3 billion
e.	6.2 million

2. A(n) __________ is a solar system object that enters Earth's atmosphere and becomes very hot due to friction between the object and Earth's atmosphere.

a.	asteroid
b.	meteor
c.	comet
d.	meteoroid
e.	planetesimal

3. The age of the solar system is believed to be approximately 4.6 billions years old based on the data from

a.	samples of lunar rocks.
b.	samples of earth rocks.
c.	samples of meteorites.
d.	all of the above
e.	none of the above.

4. Protoplanets of the Jovian planets could have grown very hot from

a.	heat for the sun.
b.	radioactivity of light elements such as hydrogen and helium.
c.	the infall of material at high velocity.
d.	tidal forces due to the sun.
e.	collisions with large planetesimals.

5. The planets all lie in nearly the same plane resulting in a disk like structure for the solar system. This disk like structure is believed to exist

a.	because the original solar nebulae had a disk-like structure.
b.	because in a rotating disk the gas atoms will quickly fall to the central disk of the spherical cloud.
c.	because Jupiter's gravity was great enough to pull all of the other planets to the plane of its orbit.
d.	because planetesimals settled into the plane.
e.	because the sun's magnetic field slowed down the rotation of the solar nebula

6. The most important effect in clearing the solar nebula of gas and dust was

a.	impacts by planetesimals.
b.	the solar wind.
c.	the sun's magnetic field.
d.	the asteroid belt.
e.	radiation pressure.

7. 51 Pegasi is unique at the moment because

a.	it is a pulsar with planets orbiting around it.
b.	it is a star with a planet that is known to support intelligent life.
c.	it is the largest satellite of Jupiter.
d.	it is the largest known asteroid.
e.	it is the only known star like our sun with a planet orbiting it.

8. On a photograph of the moon, the moon measures 30 cm in diameter and a small crater measures 0.2 cm. The moon's physical diameter is 1738 km, what is the physical diameter of the small crater?

a.	about 1738 km
b.	about 12 km
c.	about 520 km
d.	about 350 km
e.	3.5 km

9. The speed of the solar wind is approximately 400 km/s and the distance from the sun to Saturn is 9.5 AU (1 AU = 1.5 x 10⁸ km). How long does it take a particle in the solar wind to reach Saturn?

a.	about 4.1 hours
b.	about 4.1 days
c.	about 41 days
d.	about 4.1 years
e.	about 41 years

10. Suppose that Mercury grew to its present size in 1 million years through the accretion of particles averaging 100 g each. On average how many particles did Mercury capture each second? Note: Mercury has a mass of 3.3 x 10²³ kg and a radius of 2439 km.

a.	about 24 particles per second
b.	about 3.3 x 10²¹ particles per second
c.	about 67 particles per second
d.	about 100 million particles per second
e.	about 100 billion particles per second

11. The diagram below illustrates the radioactive decay of Potassium (⁴⁰K), which has a half-life of 1.3 billion years. If a lunar rock is found that currently contains 5 grams of ⁴⁰K, and it is determined that the sample contained 20 grams when it was formed, how old is the lunar rock?

a.	6.5 billion years
b.	19.5 billion years
c.	2.6 billion years
d.	3.9 billion years
e.	4.6 billion years

12. Evidence that indicates that Earth has a molten core is that

a.	no P waves penetrate the core.
b.	no S waves penetrate the core.
c.	S waves are reflected by the core.
d.	P waves are reflected by the core.
e.	neither S nor P waves are refracted by the core.

13. The oxygen in Earth's atmosphere

a.	was manufactured inside stars.
b.	was added to the atmosphere by plant life.
c.	has grown more abundant since the origin of Earth.
d.	all of these
e.	none of these

14. The greenhouse effect occurs because

a.	carbon dioxide is transparent to visible light and opaque to infrared radiation.
b.	carbon dioxide is transparent to infrared radiation and opaque to ultraviolet radiation.
c.	ozone is transparent to infrared radiation and opaque to ultraviolet radiation.
d.	ozone is transparent to visible light and opaque to infrared radiation.
e.	the sun emits more infrared radiation than ultraviolet radiation.

15. The ________ show(s) an emission spectrum and is caused by large electrical currents that flow into Earth's atmosphere near the north and south poles.

a.	Van Allen belts
b.	ozone layer
c.	lithosphere
d.	solar wind
e.	aurora

16. Saying that Earth's mantle is plastic means that

a.	Earth's mantle is made of common plastics.
b.	it has the properties of a solid but is capable of flowing under pressure.
c.	it has the properties of a liquid but because of the high pressure it transmits both P and S waves.
d.	only S waves can travel through it.
e.	only P waves can travel through it.

17. Earth possesses few visible craters and the moon possesses many. This is because

a.	Earth formed later than the moon and, therefore hasn't encountered as many meteorites.
b.	the moon doesn't have an atmosphere that could burn up many of the meteorites before impacting.
c.	erosion and plate tectonics have slowly removed evidence of past cratering on earth.
d.	all of the above
e.	only b and c

18. In the development of a planet, the stage of _____________ occurred when molten rock flowed through fissures and filled deep basins with molten rock.

a.	differentiation
b.	cratering
c.	glaciation
d.	accretion
e.	flooding

19. The diagram below shows a schematic of Earth. If an earthquake occurs at point X on Earth's surface, at which of the locations indicated by numbers would observers receive P waves from this earthquake?

a.	1 & 2
b.	3 & 4
c.	1, 2, & 3
d.	only 4
e.	all of them

20. Why would a decrease in the density of the ozone layer create a public health concern?

a.	The greenhouse effect would not be as efficient and the temperature of Earth would decrease.
b.	The greenhouse effect would be more efficient and the temperature of Earth would increase.
c.	Plant life would no longer have the ozone it needs for photosynthesis to create chlorophyll.
d.	Infrared radiation from the sun would bombard Earth and cause an increase in skin cancers.
e.	none of the above