Deck 9: Making Earth

Question 1

Figure 9.9
Using Figure 9.9 in your textbook, which element is present in the mantle in the same quantity as it is present in meteorites?

A) Ge
B) Ga
C) Al
D) Ru

Answer 1

B

Question 2

Which of the following must have occurred in order for the inner planets to grow?

A) explosions in the Sun
B) solar wind blasted gases out of the nebula
C) temperatures cooled throughout the nebula
D) dust was delivered to the nebula by asteroids and meteors

Answer 2

B

Question 3

Two billion years ago, radioactive heat production was

A) half of what it is today.
B) twice what it is today.
C) the same as it is today.
D) four times what it is today.

Answer 3

D

Question 4

Why is the inner core expanding?

A) crystallization
B) vaporization
C) melting
D) condensation

Question 5

"The oceanic crust is older than the continental crust because it is deeper." Evaluate this statement.

A) This statement is true. The continental crust floats much higher on Earth's surface than the oceanic crust.
B) This statement is false. The oceanic crust experiences more subduction and is younger than the continental crust.
C) This statement is true, but the speaker should have also mentioned that the oceanic crust is known to be older by the type of rock it is (basalt).
D) This statement is false. The land that is now considered continental was previously oceanic crust, so this comparison is meaningless.

Question 6

What is the purpose of planetary accretion gravity?

A) holds satellites in the gravity of Earth
B) pulls small particles, such as dust and debris, into larger objects
C) pulls the mass of the nebular disk to its center
D) binds particles together by hydrogen bonding

Question 7

What is defined here? "mixtures of ice and rock like dirty snowballs"

A) comets
B) meteors
C) asteroids
D) meteorites

Question 8

Which statement about the solar nebula is false?

A) It is formed as gas and dust spin faster and faster.
B) It will eventually become a Sun.
C) It will form stars and planets.
D) It requires the Sun's energy to spin.

Question 9

Figure 9.9
Using Figure 9.9 in your textbook, choose the option that sequences the elements according to what scientists think are the least abundant elements in the mantle to the most abundant elements in the mantle.

A) Pd, Au, Ge, Mn
B) V, P, Mo, Ru
C) Cr, Fe, Ag, Os
D) As, Pt, W, Ga

Question 10

Which of the following did not form in the hotter inner part of the solar system according to solar system theory?

A) water vapor
B) silicates
C) oxides
D) metal dust

Question 11

Planetary differentiation relies upon

A) heat.
B) chemical composition.
C) pressure.
D) density.

Question 12

Why did the first planetesimals form at the outer edge of the nebular disk?

A) The smaller particles were gathered at the outer edge.
B) The heat of fusion was more favorable there.
C) Cooler temperatures favored condensation there.
D) The planetary accretion gravity spun the planetesimal particles to the outer edge.

Question 13

Which of the following did not happen to Earth's original rocks?

A) They formed the base rock for some of Earth's highest mountains.
B) They were recycled in the rock cycle.
C) They were consumed by erosion.
D) They were consumed by plate tectonics.

Question 14

Which statement about solar wind is false?

A) Solar wind is created by fast-moving protons and electrons.
B) Solar wind is caused by heat in the Sun.
C) Solar wind includes periodic blasts of air.
D) Our Sun's solar winds are less intense now than in its early history.

Question 15

Present day heat flow from within Earth is twice as high as could be expected from radioactivity's contribution. This suggests that

A) more radioactivity is occurring than what scientists have accounted.
B) volcanic action contributes more than scientists presently understand.
C) Earth used to be much hotter.
D) movement within the core causes heating by friction.

Question 16

What is defined here? "A larger cluster of irregularly shaped, rocky planetesimals form an orbiting belt between Mars and Jupiter."

A) comets
B) meteors
C) asteroids
D) meteorites

Question 17

The continental crust has an average age of ________ and a maximum age of ________.

A) 1.2 billion; 3.9 billion
B) 1.6 billion; 4.0 billion
C) 1.8 billion; 3.2 billion
D) 2.2 billion; 4.4 billion

Question 18

Which option was not an effect of gravitational push and pull on planetary embryos?

A) Embryos began to accrete particles from outside of their original feeding zones.
B) The original compositional gradients from inner to outer parts of the solar system imparted by varying condensation temperatures was blurred.
C) The embryo orbits crossed one another, setting up collisions that continued the planetary accretion process to the next stage  the making of the inner rocky planets.
D) The speed of rotation was increased by accretion and some of the embryos began to break apart.

Question 19

What does a comparison of meteorite abundances of metals with samples of Earth's mantle help geochemists understand?

A) the formation of crust through volcanic action
B) the differentiation of Earth as it occurred after it formed
C) the accretion of Earth from planetesimals
D) the elements that have escaped Earth's gravity during its formation

Question 20

The oceanic crust has an average age of ________ and a maximum age of ________.

A) 200 million; 400 million
B) 80 million; 200 million
C) 100 million; 180 million
D) 90 million; 300 million

Question 21

Which piece of evidence does not point to the accretion of a wet Earth?

A) meteor water ratio compared to Earth rocks
B) Moon rocks compared to Earth rocks
C) zircon crystals in granite
D) craters on the Moon

Question 22

What explains the lack of volcanic gases, such as sulfur dioxide, hydrogen sulfide, and hydrogen chloride, in Earth's atmosphere?

A) radioactivity
B) reactions with oxygen
C) crystallization reactions
D) weathering reactions

Question 23

How much material is accreted to Earth from outer space on a daily basis?

A) 1,000,000 dust particles per day
B) 10 grams per day
C) 100,000 kg per day
D) 10,000 liters per day

Question 24

Which explanation best describes how oceanic crust is formed?

A) Continental crust is swallowed by the sea at subduction zones.
B) Oceanic crust is extracted from the mantle by partial melting and crystallization.
C) Oceanic crust crystallizes in the core and is pushed up through volcanic pipes.
D) Oceanic crust formed when magma ocean cooled and has remained unchanged except around plate boundaries and at hot spots.

Question 25

How much of the water on Earth do scientists think was delivered by comets?

A) none
B) a minor amount
C) a major amount
D) all of it

Question 26

A solar wind is not moving air but is fast-moving protons and electrons blasting outward from a star.

Question 27

The rocks that originated during or immediately after Earth's planetary formation are not preserved for study.

Question 28

Which of the following is a good analogy for planetesimal growth?

A) rolling a snowball on the ground to build a snowman
B) melting of a snowman on a warm sunny day
C) getting your tongue stuck on a frozen pipe
D) throwing a snowball through a heavy blizzard of snowflakes

Question 29

Although spectacular collisions like comet Shoemaker-Levy 9 impact with Jupiter in 1994 provide evidence that planetary accretion is still occurring, near all the mass of the solar nebula now resides in the sun and planets. When did Earth, for the most part, attain its current mass and volume?

A) 65 million years ago
B) 12,000 years ago
C) it hasn't
D) 4,500 million years ago

Question 30

What percent of a comet is water?

A) ten percent
B) thirty percent
C) fifty percent
D) eighty percent

Question 31

Figure 9.15
Using Figure 9.15 in your textbook, what is the ratio of cubic kilometers of water in ice to water in rock-forming minerals?

A) 27.5 million: 420 million
B) 420 million: 27.5 million
C) 420 million: 8.35 million
D) 1.35 billion: 420 million

Question 32

The statement that certain meteorites resemble the composition of the early mantle is

A) a hypothesis.
B) an assumption.
C) a theory.
D) an observation.

Question 33

Comets are comparable to

A) mantle inclusions.
B) Earth's core.
C) igneous rocks.
D) dirty snowballs.

Question 34

What is the role of water in the asthenosphere?

A) It forms underground lakes and rivers.
B) It composes part of many rock-forming minerals.
C) It induces the melting of rocks.
D) It acts as a solvent to dissolve rocks.

Question 35

Why is it more difficult to discern the formation processes of the continental crust versus the oceanic crust?

A) There are many more volcanoes under the ocean.
B) The continental crust is much older.
C) The oceanic crust has fewer layers and fewer types of rocks.
D) The continental crust has had more weathering, uplift, and earthquake action.

Question 36

Where did water possibly form before it formed on Earth's surface?

A) close to the core
B) the outer solar system
C) the inner solar system near the Sun
D) on the Moon

Question 37

Which observation suggests that the continental crust did not form by the same processes that presently occur on Earth?

A) The crust is largely andesitic.
B) The time frame is too slow.
C) There is more water now so the processes must be different chemically.
D) Magnetic records in the rocks show that the gravity was different.

Question 38

What scientific mistake do late-delivery hypothesis scientists claim that water-accretion hypothesis scientists made?

A) not enough data
B) biased observation methods
C) basing research on a faulty hypothesis
D) theory was not based on observations

Question 39

Most meteorites originate in the

A) Kuiper belt.
B) Astroid belt.
C) Halley's comet.
D) Sun.

Question 40

What evidence is there for the late delivery of water to an initially dry Earth?

A) craters on the Moon
B) abundance of iron-seeking minerals
C) sedimentation patterns show the early water table
D) petroleum deposits show evidence of early water deposits

Question 41

The most distinctive chemical and physical boundary within Earth is between the mantle and core.

Question 42

After about 100,000 years, what is the internal temperature of a nebular disk?

A) 3 000 degrees
B) 4 000 degrees
C) 100 000 degrees
D) 1 million degrees

Question 43

Why did the first planetesimals form at the outer edge of the nebular disk?

A) The smaller particles were gathered at the outer edge.
B) The heat of fusion was more favorable there.
C) Cooler temperatures favored condensation there.
D) The planetary accretion gravity spun the planetesimal particles to the outer edge.

Question 44

Earth was once much, much hotter than it is today?

Question 45

Evidence that scientists would not utilize to study Earth's formation is

A) Moon rocks.
B) core samples.
C) meteorite rocks.
D) data from other planets.

Question 46

Earth's early atmosphere contained abundant oxygen.

Question 47

Determination of the origin of continental crust is more complicated than determining the origin of oceanic crust.

Question 48

Which of the following is a good analogy for planetary differention?

A) scrambling an egg to make an omelet
B) a salad dressing of oil and vinegar
C) throwing a snowball through a heavy blizzard of snowflakes
D) dust particles clumping together under your bed

Question 49

What determines the chemical composition of the dust particles that form around a protostar?

A) heat
B) pressure
C) contents of the star that exploded to form the protostar
D) gravity of nearby objects

Question 50

Oceans of water and continental crust were present

A) 150 000 000 years after Earth formed.
B) 2 000 000 000 years after Earth formed.
C) 15 000 000 years after Earth formed.
D) 75 000 000 years after Earth formed.

Question 51

Which statement about solar wind is false?

A) Solar wind is created by fast-moving protons and electrons.
B) Solar wind is caused by heat in the Sun.
C) Solar wind includes periodic blasts of air.
D) Our Sun's solar winds are less intense now than in its early history.

Question 52

What evidence did the Hubble Space Telescope provide to support the nebular theory of solar system formation?

A) proof of the spinning of our solar system
B) proof of the expansion of our solar system
C) pictures of other spinning stars
D) pictures of other stars with dust and gas

Question 53

The oldest grain of sand found and dated is made of

A) zircon.
B) diamond.
C) peridotite.
D) basalt.

Question 54

Read carefully through the paragraph below, and decide which of the options is correct. Intermediate and felsic continental crust can form by simple mantle melting. Physical separation of metamorphosed mafic igneous rocks may leave behind typical, more felsic crust. Partial melting of basaltic oceanic crust in hot early Earth may have generated magmas with continental-crust composition that form rarely today

A) The word " rarely " should be replaced by "abundantly".
B) The word "can" should be replaced by "cannot".
C) The word " separation " should be replaced by "mixing".
D) The word " Partial " should be replaced by "Total".

Question 55

Which of the following are the correct inner planets?

A) Mercury, Venus, Earth, Mars
B) Earth, Mars, Jupiter, Saturn
C) Jupiter, Saturn, Uranus, Neptune
D) Mercury, Earth, Saturn, Neptune

Question 56

There is direct geologic evidence about Earth's earliest crust.

Question 57

Which planets contain mostly hydrogen atmospheres?

A) Mercury, Venus, and Mars
B) Jupiter, Saturn, and Uranus
C) Mars, Jupiter, and Saturn
D) Uranus, Neptune, and Pluto

Question 58

Which of the following are the correct outer planets?

A) Mercury, Venus, Earth, Mars
B) Earth, Mars, Jupiter, Saturn
C) Jupiter, Saturn, Uranus, Neptune
D) Mercury, Earth, Saturn, Neptune

Question 59

The largest reservoir of water on, below or above Earth's surface is/are

A) lakes and rivers.
B) the oceans.
C) the atmosphere.
D) water-bearing rocks.

Question 60

Differentiation of planetary embryos results in denser ________ cores and less-dense ________ mantles.

A) silicate, non-silicate
B) metallic, silicate
C) silicate, metallic
D) non-metallic, metallic

Question 61

Oxygen most likely accumulated in the atmosphere very gradually after the appearance of photosynthetic organisms, which consume carbon dioxide while manufacturing oxygen.

Question 62

The final accretion of Earth is thought to have included giant embryo collisions.

Question 63

How did the hydrosphere and atmosphere form?

Question 64

The disk-shaped cloud that formed our solar system is called the solar nebula because:

A) the concentrated mass near the center eventually forms into the Sun.
B) it is whirled around by solar wind.
C) the spinning disk was infinitely brighter than the rest of the solar system.
D) None of the above is correct.

Question 65

Explain the origin of oceanic crust.

Question 66

A planet is a celestial body that

A) orbits the sun.
B) has sufficient mass and therefore gravitational pull to form into a nearly spherical shape.
C) cleared all other objects from the neighborhood of its orbit.
D) All of the above are correct.

Question 67

Under the physical influence of gravity, the heavy, dense iron sank to form the core, leaving the less dense silicates to form the mantle.

Question 68

What evidence do geologists have that Earth was once hotter than it is today?

Question 69

Although the iron sank to the core, most of the "strongly" iron-seeking elements remained behind.

Question 70

Meteorites are called meteoroids when they land on the surface.

Question 71

What happened to the "leftovers" from the formation of our solar system?

Question 72

How did the core and mantle form?

Question 73

Is the accretion process of Earth over?

Question 74

Planetary accretion is the process that gradually accumulates small particles into large different parts of the nebular disk, because of the different condensation temperatures of particles at various distances from the hot protosun.