Question 1

In general, which things below are affected by a magnetic field?

Accepted Answer

A) charged particles or magnetized materials (such as iron) 
B) iron- bearing minerals only 
C) gases and liquids 
D) rocks of all types

Question 2

Rank the five terrestrial worlds in order of size from smallest to largest.

Accepted Answer

A) Mercury, Moon, Venus, Earth, Mars 
B) Moon, Mercury, Venus, Earth, Mars 
C) Mercury, Venus, Earth, Moon, Mars 
D) Moon, Mercury, Mars, Venus, Earth 
E) Mercury, Moon, Mars, Earth, Venus

Question 3

Why are there fewer large impact craters on the Earth's seafloor than on the continents?

Accepted Answer

A) Seafloor crust is younger than continental crust, so it has had less time in which to suffer impacts. 
B) Erosion erases impact craters must faster on the ocean bottom than on land. 
C) The oceans slow large impactors and prevent them from making craters. 
D) Most impacts occur on the land.

Question 4

Which two factors are most important to the existence of plate tectonics on Earth?

Accepted Answer

A) mantle convection and a thin lithosphere 
B) oxygen in the atmosphere and mantle convection 
C) Earth's liquid outer core and solid inner core 
D) the existence of life and oxygen in the atmosphere

Question 5

A planet is most likely to have tectonic activity if it has

Accepted Answer

A) high internal temperature. 
B) high surface gravity. 
C) a dense atmosphere. 
D) low internal temperature. 
E) low surface gravity.

Question 6

What is the most important factor that determines the thickness, and therefore strength, of the lithosphere?

Accepted Answer

A) distance of planet from Sun 
B) internal temperature 
C) pressure 
D) composition

Question 7

What is the importance of the carbon dioxide (CO₂)cycle?

Accepted Answer

A) It makes the growth of continents possible. 
B) It regulates the carbon dioxide concentration of our atmosphere, keeping temperatures moderate. 
C) It allows for an ultraviolet- absorbing stratosphere. 
D) It will prevent us from suffering any consequences from global warming.

Question 8

Which of the following best describes convection?

Accepted Answer

A) It is the process in which a liquid separates according to density, such as oil and water separating in a jar. 
B) It is the process in which bubbles of gas move upward through a liquid. 
C) It is the process in which warm material gets even warmer and cool material gets even cooler. 
D) It is the process by which rocks sink in water. 
E) It is the process in which warm material expands and rises while cool material contracts and falls.

Question 9

Rank these planets in order of the strength of the greenhouse effect on the planet, from the least to the greatest.

Accepted Answer

A) Mars, Earth, Venus, Mercury 
B) Mercury, Venus, Earth, Mars 
C) Mars, Mercury, Earth, Venus 
D) Mercury, Earth, Mars, Venus 
E) Mercury, Mars, Earth, Venus

Question 10

Briefly explain why Mercury, Venus, and the Moon do not have significant erosion. Relate erosional activity to planetary size and distance from the Sun.

Accepted Answer

The answer of Briefly explain why Mercury, Venus, and the...

Question 11

What kind of surface features may result from tectonics?

Accepted Answer

A) volcanos 
B) mountains 
C) cliffs 
D) valleys 
E) all of the above

Question 12

On average, how fast do the plates move on the Earth?

Accepted Answer

A) about 1 mile per hour 
B) a few centimeters per year 
C) a few kilometers per year 
D) a few millimeters per century

Question 13

What makes us think that Mars must once have had an atmosphere that was warmer and had higher surface pressure?

Accepted Answer

A) We think it for purely theoretical reasons, based on calculations showing that the Sun has brightened with time. 
B) The fact that parts of Mars have a lot of craters tell us that Mars must once have been much warmer. 
C) The atmosphere is too cold and thin for liquid water today, yet we see evidence that water flowed on the surface in the past. 
D) The presence of inactive volcanoes on Mars tells us that there must once have been a lot of outgassing, and hence a thicker atmosphere.

Question 14

Sunsets are red because sunlight must pass through more atmosphere then, and the atmosphere scatters even more light at bluer wavelengths, leaving mostly red light to color the sky.

Accepted Answer

A) True 
 B)False

Question 15

All the following statements about Mars are true. Which one might have led to a significant loss of atmospheric gas to space?

Accepted Answer

A) Mars probably once had a much higher density of greenhouse gases in its atmosphere than it does today. 
B) The axis tilt of Mars is thought to change significantly with time. 
C) Mars lost any global magnetic field that it may once have had. 
D) Outgassed water molecules are split apart by ultraviolet light, and the oxygen then reacts chemically with surface rock on Mars.

Question 16

The choices below describe four hypothetical planets. Which one would you expect to have the hottest interior? (Assume the planets orbit a star just like the Sun and that they are all the same age as the planets in our solar system.)

Accepted Answer

A) Size: same as Mars. Distance from Sun: same as Earth. Rotation rate: once every 18 hours. 
B) Size: same as Venus. Distance from Sun: same as Mars. Rotation rate: once every 25 hours. 
C) Size: twice as big as Earth. Distance from Sun: same as Mercury. Rotation rate: once every 6 months. 
D) Size: same as the Moon. Distance from Sun: same as Mars. Rotation rate: once every 10 days.

Question 17

What is the "runaway greenhouse effect"?

Accepted Answer

The answer of What is the "runaway greenhouse effect"?...

Question 18

Why is the sky blue (on Earth)?

Accepted Answer

A) because deep space is blue in color 
B) because molecules scatter red light more effectively than blue light 
C) because the Sun emits mostly blue light 
D) because molecules scatter blue light more effectively than red light 
E) No one knows-this is one of the great mysteries of science.

Question 19

Suppose Mars had turned out to be significantly smaller than its current size, say about the size of our Moon. How would this have affected the number of geological features due to each of the four major geological processes?

Accepted Answer

The answer of Suppose Mars had turned out to be...

Question 20

What is a magnetosphere?

Accepted Answer

A) a region of space around a planet in which the planet's magnetic field can trap charged particles 
B) the uppermost layer of any planetary atmosphere 
C) the region in a planet's atmosphere in which auroras occur 
D) the layer of a planet in which its magnetic field is generated

Exam 7: Earth and the Terrestrial Worlds