Question 1

What is the origin of Earth's water?

Accepted Answer

Water is believed to have been brought to Earth by comets dislodged from their orbits by the giant planets of our solar system.Water was also delivered to Earth's surface by the outgassing of volcanoes.

Question 2

The majority of the nitrogen in the air we breathe today was originally in what form?

Accepted Answer

A)  amino acids 
B)  ammonia 
C)  hydrocarbons 
D)  halogens 
E)  atomic nitrogen gas emitted by the Sun. 
A)  amino acids 
B)  ammonia 
C)  hydrocarbons 
D)  halogens 
E)  atomic nitrogen gas emitted by the Sun. B

Question 3

The greenhouse effect raises Earth's surface temperature by roughly

Accepted Answer

A)  0 K. 
B)  0.35 K. 
C)  3.5 K. 
D)  35 K. 
E)  350 K. 
A)  0 K. 
B)  0.35 K. 
C)  3.5 K. 
D)  35 K. 
E)  350 K. D

Question 4

If sunlight broke up water molecules in Venus's atmosphere, would the hydrogen atoms escape into outer space? Note that Venus's temperature is 740 K.Recall that gas eventually will escape if the average velocity of its atoms is greater than 1/6 times the escape velocity of the planet.The escape velocity of Venus is 10 km/s.

Accepted Answer

A)  No, the average velocity of hydrogen atoms would be 0.8 km/s. 
B)  No, the average velocity of hydrogen atoms would be 3.9 km/s. 
C)  Yes, the average velocity of hydrogen atoms would be 3.9 km/s. 
D)  Yes, the average velocity of hydrogen atoms would be 25 km/s. 
E)  No, the average velocity of hydrogen atoms would be 25 km/s. 
A)  No, the average velocity of hydrogen atoms would be 0.8 km/s. 
B)  No, the average velocity of hydrogen atoms would be 3.9 km/s. 
C)  Yes, the average velocity of hydrogen atoms would be 3.9 km/s. 
D)  Yes, the average velocity of hydrogen atoms would be 25 km/s. 
E)  No, the average velocity of hydrogen atoms would be 25 km/s.

Question 5

According to the following figure, about how long ago did oxygen reach its current abundance in Earth's atmosphere?

Accepted Answer

A)  3 billion years ago 
B)  1 billion years ago 
C)  0.5 billion years ago 
D)  0.25 billion years ago 
E)  0.1 billion years ago 
A)  3 billion years ago 
B)  1 billion years ago 
C)  0.5 billion years ago 
D)  0.25 billion years ago 
E)  0.1 billion years ago

Question 6

When frozen water on the surface of Mars heats up during summertime, the water

Accepted Answer

A)  melts and forms liquid pools on the surface. 
B)  boils off the surface and escapes into outer space. 
C)  sublimates and goes directly into the gaseous phase. 
D)  remains frozen because the temperature remains below the freezing point. 
E)  melts and creates flowing rivers that erode the landscape. 
A)  melts and forms liquid pools on the surface. 
B)  boils off the surface and escapes into outer space. 
C)  sublimates and goes directly into the gaseous phase. 
D)  remains frozen because the temperature remains below the freezing point. 
E)  melts and creates flowing rivers that erode the landscape.

Question 7

If it were not for the greenhouse effect on Earth,

Accepted Answer

A)  there would be no liquid water on Earth. 
B)  life as we know it would not have developed on Earth. 
C)  it would be a much colder planet. 
D)  there would be no oxygen in Earth's atmosphere. 
E)  All of these are results of the greenhouse effect. 
A)  there would be no liquid water on Earth. 
B)  life as we know it would not have developed on Earth. 
C)  it would be a much colder planet. 
D)  there would be no oxygen in Earth's atmosphere. 
E)  All of these are results of the greenhouse effect.

Question 8

Over the last century, why has the ozone hole over Earth grown larger? How long might it take to revert to its former state?

Accepted Answer

The ozone hole has grown because chemica

Question 9

If sunlight cannot penetrate Venus's cloud layer efficiently, why does the temperature of the planet remain so high?

Accepted Answer

Sunlight is still absorbed,partially,by

Question 10

The absence of oxygen on Mars means that it has very little

Accepted Answer

A)  carbon dioxide. 
B)  methane. 
C)  ozone. 
D)  helium. 
E)  ammonia 
A)  carbon dioxide. 
B)  methane. 
C)  ozone. 
D)  helium. 
E)  ammonia

Question 11

Each halogen atom, such as chlorine, fluorine, and bromine, in Earth's atmosphere contributes to

Accepted Answer

A)  the production of carbon dioxide. 
B)  the production of acid rain. 
C)  the destruction of ozone over decades and centuries. 
D)  the destruction of water in the upper atmosphere. 
E)  the production of limestone. 
A)  the production of carbon dioxide. 
B)  the production of acid rain. 
C)  the destruction of ozone over decades and centuries. 
D)  the destruction of water in the upper atmosphere. 
E)  the production of limestone.

Question 12

According to the figure below, approximately how many years ago did oxygen finally get to half its current abundance in Earth's atmosphere?

Accepted Answer

A)  3 billion years ago 
B)  1 billion years ago 
C)  0.6 billion years ago 
D)  0.25 billion years ago 
E)  0.1 billion years ago 
A)  3 billion years ago 
B)  1 billion years ago 
C)  0.6 billion years ago 
D)  0.25 billion years ago 
E)  0.1 billion years ago

Question 13

The minimum amount of oxygen in the air required for a human to survive (unaided) is around 16 percent of the current abundance in Earth's atmosphere.Using the figure below, what is the earliest time in Earth's history that a human could breathe unaided?

Accepted Answer

Estimating from the

Question 14

Which molecule moves with the fastest average speed while being bound in Earth's atmosphere in thermal equilibrium?

Accepted Answer

A)  water, H2O (atomic mass = 18) 
B)  carbon dioxide, CO2 (atomic mass =44) 
C)  nitrogen (atomic mass= 28) 
D)  oxygen (atomic mass = 32) 
E)  hydrogen, H2 (atomic mass = 2) 
A)  water, H2O (atomic mass = 18) 
B)  carbon dioxide, CO2 (atomic mass =44) 
C)  nitrogen (atomic mass= 28) 
D)  oxygen (atomic mass = 32) 
E)  hydrogen, H2 (atomic mass = 2)

Question 15

Give two reasons why the atmosphere of Earth is warmer near the surface than at higher elevations.

Accepted Answer

(1)The lower portion of the atmosphere i

Question 16

Would a nitrogen atom in Venus's atmosphere, whose temperature is 740 K, eventually escape into outer space? Note that a nitrogen atom has a mass that is 14 times that of a hydrogen atom.Recall that atoms eventually will escape if their average velocity is greater than 1/6 times the escape velocity of the planet.The escape velocity of Venus is 10 km/s.For comparison, a hydrogen atom has an average velocity of 2.5 km/s at a temperature of 300 K.

Accepted Answer

A)  The average velocity of nitrogen atoms is 0.4 km/s, and nitrogen does not escape. 
B)  The average velocity of nitrogen atoms is 1.0 km/s, and nitrogen does not escape. 
C)  The average velocity of nitrogen atoms is 1.0 km/s, and nitrogen escapes. 
D)  The average velocity of nitrogen atoms is 4.5 km/s, and nitrogen does not escape. 
E)  The average velocity of nitrogen atoms is 4.5 km/s, and nitrogen escapes. 
A)  The average velocity of nitrogen atoms is 0.4 km/s, and nitrogen does not escape. 
B)  The average velocity of nitrogen atoms is 1.0 km/s, and nitrogen does not escape. 
C)  The average velocity of nitrogen atoms is 1.0 km/s, and nitrogen escapes. 
D)  The average velocity of nitrogen atoms is 4.5 km/s, and nitrogen does not escape. 
E)  The average velocity of nitrogen atoms is 4.5 km/s, and nitrogen escapes.

Question 17

The major difference in the composition of Earth's atmosphere compared to the atmospheres of Venus and Mars is a direct consequence of

Accepted Answer

A)  life on Earth. 
B)  Earth's plate tectonics. 
C)  differences in the greenhouse effect. 
D)  the presence of liquid water. 
E)  differing distances from the Sun. 
A)  life on Earth. 
B)  Earth's plate tectonics. 
C)  differences in the greenhouse effect. 
D)  the presence of liquid water. 
E)  differing distances from the Sun.

Question 18

In the stratosphere of Earth's atmosphere, how does the temperature vary with increasing altitude, and what causes this variation?

Accepted Answer

Ozone in the stratosphere absorbs UV lig

Question 19

Venus's rotation is such that the dominant form of atmospheric circulation is powered by

Accepted Answer

A)  winds moving from its equator to its poles. 
B)  heated air escaping from its volcanoes moving along the equator. 
C)  winds moving from its poles to its equator. 
D)  heated air escaping from active tectonic plates. 
E)  radioisotope decays. 
A)  winds moving from its equator to its poles. 
B)  heated air escaping from its volcanoes moving along the equator. 
C)  winds moving from its poles to its equator. 
D)  heated air escaping from active tectonic plates. 
E)  radioisotope decays.

Question 20

Give three reasons why we believe Venus may currently have active volcanoes.

Accepted Answer

(1)The presence of "hot spots" near volc

Exam 9: Atmospheres of the Terrestrial Planets

What is the origin of Earth's water?

The majority of the nitrogen in the air we breathe today was originally in what form?

The greenhouse effect raises Earth's surface temperature by roughly

According to the following figure, about how long ago did oxygen reach its current abundance in Earth's atmosphere?

When frozen water on the surface of Mars heats up during summertime, the water

If it were not for the greenhouse effect on Earth,

Over the last century, why has the ozone hole over Earth grown larger? How long might it take to revert to its former state?

If sunlight cannot penetrate Venus's cloud layer efficiently, why does the temperature of the planet remain so high?

The absence of oxygen on Mars means that it has very little

Each halogen atom, such as chlorine, fluorine, and bromine, in Earth's atmosphere contributes to

According to the figure below, approximately how many years ago did oxygen finally get to half its current abundance in Earth's atmosphere?

The minimum amount of oxygen in the air required for a human to survive (unaided) is around 16 percent of the current abundance in Earth's atmosphere.Using the figure below, what is the earliest time in Earth's history that a human could breathe unaided?

Which molecule moves with the fastest average speed while being bound in Earth's atmosphere in thermal equilibrium?

Give two reasons why the atmosphere of Earth is warmer near the surface than at higher elevations.

The major difference in the composition of Earth's atmosphere compared to the atmospheres of Venus and Mars is a direct consequence of

In the stratosphere of Earth's atmosphere, how does the temperature vary with increasing altitude, and what causes this variation?

Venus's rotation is such that the dominant form of atmospheric circulation is powered by

Give three reasons why we believe Venus may currently have active volcanoes.

Thinking Like an Astronomer

Patterns in the Skymotions of Earth and the Moon

Motion of Astronomical Bodies

Gravity and Orbits

Light

The Tools of the Astronomer

The Formation of Planetary Systems

The Terrestrial Planets and Earths Moon

Worlds of Gas and Liquidthe Giant Planets

Planetary Moons and Rings

Dwarf Planets and Small Solar System Bodies

Taking the Measure of Stars

Our Starthe Sun

The Interstellar Medium and Star Formation

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

Relativity and Black Holes

Galaxies

The Milky Waya Normal Spiral Galaxy

The Expanding Universe

Cosmology

Large-Scale Structure in the Universe

Life

Filters