Chapter 10
Basic Skills/Definitions Quiz
Part A
Which of the following correctly lists the terrestrial worlds in order from the thickest atmosphere to the thinnest atmosphere? Note: Mercury and the Moon are considered together in this question.
Hint A.1
Study Section 10.1
ANSWER:

Venus, Mars, Moon/Mercury, Earth Mars, Venus, Earth, Moon/Mercury Earth, Venus, Mars, Moon/Mercury Venus, Earth, Mars, Moon/Mercury
Part B
Which planet or planets have an atmosphere that consists mostly of carbon dioxide?
Hint B.1
Study Section 10.1
ANSWER:

Venus, Earth, and Mars Venus and Mars Venus only Mars only
Part C
Why does atmospheric pressure decrease as you go higher in altitude on Earth?
Hint C.1
Study Section 10.1
ANSWER:

Gravity gets much weaker with altitude. The weight of the atmosphere above you decreases with altitude. Temperature decreases with altitude and lower temperature tends to mean lower pressure. There are fewer greenhouse gases at higher altitude.
Part D
In the context of a planetary atmosphere, what is a bar?
Hint D.1
Study Section 10.1
ANSWER:

A unit of pressure roughly equal to the atmospheric pressure at sea level on Earth. A place to get sodas and other drinks. The pressure generated by placing a heavy iron bar on a balloon. A unit of pressure roughly equal to the pressure underwater at a depth of 1 kilometer.
Part E
Which of the following is NOT a greenhouse gas?
Hint E.1
Study Section 10.1
ANSWER:

carbon dioxide (CO2) water vapor (H2O) methane (CH4) oxygen (O2)
Part F
All of the statements below are true. Which one gives the primary reason why the surface of Venus today is some 450°C hotter than the surface of Earth?
Hint F.1
Study Section 10.1
ANSWER:

Venus has a much stronger greenhouse effect than Earth. Venus has a much higher reflectivity than Earth. Venus is only about 73% as far from the Sun as Earth. Venus has a higher atmospheric pressure than Earth.
Part G
Suppose that Earth's atmosphere had no greenhouse gases. Then the Earth's average surface temperature would be:
Hint G.1
Study Section 10.1
ANSWER:

Slightly warmer, but still below the boiling point of water. Some 30°C cooler, which means well below the freezing point of water. Slightly cooler, but still above freezing. About the same as it is now.
Part H
Which of the following correctly lists the layers of Earth's atmosphere from the ground upward?
Hint H.1
Study Section 10.1
ANSWER:

troposphere, thermosphere, stratosphere, exosphere. thermosphere, stratosphere, troposphere , exosphere. exosphere, stratosphere, thermosphere, troposphere. troposphere, stratosphere, thermosphere, exosphere.
Part I
Why is the sky blue (on Earth)?
Hint I.1
Study Section 10.1
ANSWER:

Because deep space is blue in color. Because molecules scatter blue light more effectively than red light. Because molecules scatter red light more effectively than blue light. Because the Sun emits mostly blue light.
Part J
Which of the following general statements about light and Earth's atmosphere is NOT true?
Hint J.1
Study Section 10.1
ANSWER:

Visible light from the Sun is absorbed in the exosphere. Ultraviolet from the Sun is absorbed in the stratosphere. X-rays from the Sun are absorbed in the thermosphere. Infrared light emitted by Earth itself is absorbed in the troposphere.
Part K
What is a magnetosphere?
Hint K.1
Study Section 10.1
ANSWER:

The uppermost layer of any planetary atmosphere. The layer of a planet in which its magnetic field is generated. A region of space around a planet in which the planet's magnetic field can trap charged particles. The region in a planet's atmosphere where aurorae occur.
Part L
What is the difference between weather and climate?
Hint L.1
Study Section 10.2
ANSWER:

Weather refers to atmospheric conditions in the troposphere, while climate refers to atmospheric conditions in the stratosphere. Weather refers to small storms and climate refers to large storms. Weather refers to short-term changes in wind, rain, and temperature, while climate refers to the long-term average of weather. Weather is something that we can control, and climate is not.
Part M
Which of the following describes a primary role of global circulation cells in a planet's atmosphere?
Hint M.1
Study Section 10.2
ANSWER:

They transport heat from the equator toward the poles. They create severe weather such as thunderstorms. They keep the poles cold enough to have polar caps. They cause air to be diverted into hurricane-like swirls.
Part N
What important change in the Sun over the past four billion years is thought to be very important to understanding the climates of Venus, Earth, and Mars?
Hint N.1
Study Section 10.2
ANSWER:

A gradual reduction in the amount of ultraviolet and X-ray radiation coming from the Sun. A gradual weakening of the solar wind with time. A gradual dimming with time. A gradual brightening with time.
Part O
Which of the following best describes the nature and origin of the atmospheres of the Moon and Mercury?
Hint O.1
Study Section 10.3
ANSWER:

They essentially have thin exospheres only, with gas coming from bombardment. They essentially have thin exospheres only, and the gas is leftover from outgassing long ago. They have very thin atmospheres, but still have the layers of a troposphere, thermosphere, and exosphere. Their gas comes from very tiny amounts of outgassing. They essentially have thin tropspheres only, with gas coming from evaporation and sublimation.
Part P
Which of the following is NOT a characteristic of the seasons on Mars?
Hint P.1
Study Section 10.4
ANSWER:

As on Earth, the seasons are caused primarily by axis tilt and orbital distance has virtually no effect. Global winds tend to blow from the summer pole toward the winter pole, sometimes initiating global sand storms. The polar caps shrink in summer and grow in winter. The seasons last almost twice as long on Mars as on Earth.
Part Q
According to current science, why is Mars red?
Hint Q.1
Study Section 10.4
ANSWER:

The red color is caused by water ice chemically bound in surface rock. The red color of Mars is a result of the scattering of light in the Martian sky. Martian volcanoes released a much redder lava than volcanoes on Earth. Chemical reactions between surface rock and atmospheric oxygen literally rusted the surface.
Part R
What do we mean by a runaway greenhouse effect?
Hint R.1
Study Section 10.5
ANSWER:

A greenhouse effect that heats a planet so much that its surface rock melts. When a small amount of greenhouse warming adds more greenhouse gases, leading to more warming and more gases, until all a planet's greenhouse gases are in its atmosphere. A greenhouse effect that starts on a planet but later disappears as gases are lost to space. It gets its name because it heats a planet like a greenhouse effect, but it involves a completely different mechanism of heating that doesn't actually involve greenhouse gases.
Part S
Based on everything we have learned about Venus and Mars, what is the most surprising aspect of Earth's climate history?
Hint S.1
Study Section 10.6
ANSWER:

That the temperature of our planet has remained relatively steady throughout our planet's history. That Earth had enough water to form oceans. That Earth apparently got a lot of atmospheric gas from outgassing by volcanoes. That Earth's climate can be affected by changes in its axis tilt.
Part T
Which of the following statements about ozone (in Earth's stratosphere) is NOT true:
Hint T.1
Study Section 10.6
ANSWER:

Ozone absorbs harmful ultraviolet light from the Sun. If the ozone layer is depleted we can expect the rate of mutations in land-based lifeforms to increase significantly. The presence of ozone was crucial to the origin of life some 4 billion years ago. The ozone hole that appears during Antarctic spring appears to be caused by human-made CFCs.
Part U
How did oxygen (O2) get into Earth's atmosphere?
Hint U.1
Study Section 10.6
ANSWER:

It was captured from the solar nebula. It came from chemical reactions with surface rocks. It was released by life through the process of photosynthesis. It was outgassed from volcanoes.
Part V
What is the importance of the carbon dioxide (CO2) cycle?
Hint V.1
Study Section 10.6
ANSWER:

It makes the growth of continents possible. It regulates the carbon dioxide concentration of our atmosphere, keeping temperatures moderate. It allows for an ultraviolet-absorbing stratosphere. It will prevent us from suffering any consequences from global warming.
Part W
In the context of Earth's climate history, what do we mean by snowball Earth?
Hint W.1
Study Section 10.6
ANSWER:

This term is used to describe all the ice ages that have occurred in the past few million years. It is what we expect to see happen on Earth in about a billion years. A very deep ice age in which the global average temperature may have fallen well below freezing. It refers to a time when polar regions had much more snowfall than normal.
Part X
Which of the following would NOT be an expected consequence of global warming?
Hint X.1
Study Section 10.6
ANSWER:

Melting of polar ice and glaciers. An increase in the number and intensity of hurricanes. The entire Earth will warm up by the same amount. An increase in the severity of winter blizzards.