Deck 4: The Habitability of Earth

Question 1

Igneous rocks subjected to heat and pressure beneath the surface of the Earth (assume no melting occurs) transform into

A) metamorphic rocks
B) meteorites
C) other sedimentary rocks
D) igneous rocks

Answer 1

metamorphic rocks

Question 2

Rocks are found on the surface of another planet which appear to have been formed at the bottom of an ancient ocean. Given this, they are most likely to be classified as

A) Metamorphic
B) Igneous
C) Meteoritic
D) Sedimentary

Answer 2

Sedimentary

Question 3

What do we mean by the "fossil record"?

A) rocks from earlier periods of the Earth's history
B) samples of meteorites that fell to Earth early in its history
C) remains of ancient organisms preserved in rocks
D) an album by the Rolling Stones

Answer 3

remains of ancient organisms preserved in rocks

Question 4

Granite is a common type of

A) meteoritic rock
B) metamorphic rock
C) igneous rock
D) sedimentary rock

Question 5

When a sedimentary rock is melted and then re-solidifies it turns into

A) an igneous rock
B) a meteorite
C) a metamorphic rock
D) another sedimentary rock

Question 6

Sedimentary rocks subjected to heat and pressure beneath the surface of the Earth (assume no melting occurs) transform into

A) metamorphic rocks
B) Meteorites
C) other sedimentary rocks
D) igneous rocks

Question 7

How are the "geological record" and the "fossil record" related?

A) the geological and fossil records are completely unrelated
B) the fossil record is part of the geological record
C) the geological record is part of the fossil record
D) the geological record and the fossil record are just different names for the same thing

Question 8

Which component of Earth's geology has helped to shield the Earth's atmosphere from energetic particles of solar wind from the Sun which would have gradually stripped it away into space?

A) Volcanism
B) seismic activity
C) plate tectonics
D) global magnetism

Question 9

Which component of Earth's geology is believed to have been largely responsible for the long-term climate stability that has allowed life to evolve?

A) global magnetism
B) seismic activity
C) plate tectonics
D) erosion and weathering

Question 10

Basalt is a common type of

A) meteoritic rock
B) sedimentary rock
C) igneous rock
D) metamorphic rock

Question 11

Rocks are found on the surface of another planet which appear to have once been transformed at high temperatures deep within the planet. Given this, they are most likely to be classified as

A) Igneous
B) Meteoritic
C) Sedimentary
D) Metamorphic

Question 12

The Earth owes its habitability primarily to

A) the chemical composition of its surface
B) a combination of its size and its distance from the Sun
C) its size
D) its distance from the Sun

Question 13

When an igneous rock is eroded and then becomes deposited at the bottom of an ocean it turns into

A) a metamorphic rock
B) a meteorite
C) another igneous rock
D) a sedimentary rock

Question 14

Sandstone is a common type of

A) meteoritic rock
B) sedimentary rock
C) metamorphic rock
D) igneous rock

Question 15

What do we mean by the "geological record"?

A) rocks from earlier periods of the Earth's history
B) samples of meteorites that fell to Earth early in its history
C) remains of ancient organisms preserved in rocks
D) an album by the Rolling Stones

Question 16

Limestone is a common type of

A) metamorphic rock
B) meteoritic rock
C) igneous rock
D) sedimentary rock

Question 17

Rocks are found on the surface of another planet which appear to have been formed from the solidification of molten lava. Given this, they are most likely to be classified as

A) Meteoritic
B) Metamorphic
C) Sedimentary
D) Igneous

Question 18

When a metamorphic rock is eroded and then becomes deposited at the bottom of an ocean it turns into

A) a meteorite
B) an igneous rock
C) a sedimentary rock
D) another metamorphic rock

Question 19

When a metamorphic rock is melted and then re-solidifies it turns into

A) an igneous rock
B) a sedimentary rock
C) a meteorite
D) another metamorphic rock

Question 20

Which of the following processes is believed to have been an important source of the Earth's atmosphere?

A) outgassing by volcanoes on the Earth's surface
B) gas trapped from the solar nebula
C) matter blasted from the surface of the Moon
D) charged particles trapped from the Sun

Question 21

A radioactive isotope with an atomic number of 92 undergoes alpha decay. What is the atomic number of the daughter nucleus?

A) 93
B) 90
C) 91
D) 94

Question 22

In which type of radioactive decay does the atomic number of the parent nucleus change?

A) the atomic number changes in all three types of decay
B) electron capture
C) beta decay
D) alpha decay

Question 23

A fossil is found in a layer of strata above another layer dated at 10 million years and below another layer dated at 5 million years. From this we can deduce the age of the fossil to be

A) older than 10 million years
B) younger than 5 million years
C) we can tell nothing about the fossil's age from this data
D) between 5 and 10 million years old

Question 24

In alpha decay,

A) a proton turns into a neutron
B) a neutron turns into a proton
C) a proton turns into an electron
D) a helium nucleus is ejected

Question 25

In which type or types of radioactive decay does the mass number of the parent nucleus change?

A) electron capture only
B) beta decay only
C) alpha decay only
D) beta decay and electron capture

Question 26

The radioactive isotope ²²⁶Ra (atomic number 88) decays to the isotope ²²²Rn (atomic number 86). What type of radioactive decay is this?

A) beta decay
B) electron ionization
C) electron capture
D) alpha decay

Question 27

What do we mean by the half-life of a radioactive isotope?

A) it is the amount of time a person can be exposed to radiation without getting sick
B) it is the time for half the number of radioactive nuclei in a sample to become stable nuclei
C) it is the amount of time for half of the nuclei in a sample to become radioactive
D) it is the time for half the number of radioactive nuclei in a sample to decay

Question 28

Mineralogical analysis of a rock can tell us

A) the detailed geological history of the rock
B) what the rock is made of
C) when the rock formed
D) the temperature and pressure conditions under which it formed

Question 29

A radioactive isotope is

A) an unstable nucleus that gives off radio waves
B) a nucleus that formed from the fusion of two other nuclei
C) a stable nucleus that is formed from the fission of a large unstable nucleus
D) an unstable nucleus that spontaneously decays to produce high-energy particles and radiation

Question 30

A fossil is found in a layer of strata above one layer dated at 2 million years. From this we can deduce the age of the fossil to be

A) we can tell nothing about the fossil's age from this data
B) younger than 2 million years
C) between 2 and 3 million years old
D) older than 3 million years

Question 31

In beta decay,

A) a neutron turns into a proton
B) a helium nucleus is ejected
C) a proton turns into an electron
D) a proton turns into a neutron

Question 32

The radioactive isotope ⁷Be (atomic number 4) decays to the isotope ⁷Li (atomic number 3). What type of radioactive decay is this?

A) electron capture
B) beta decay
C) electron ionization
D) alpha decay

Question 33

A radioactive isotope with an atomic number of 37 undergoes electron capture. What is the atomic number of the daughter nucleus?

A) 35
B) 34
C) 38
D) 36

Question 34

The radioactive isotope ¹³¹I (atomic number 53) decays to the isotope ¹³¹Xe (atomic number 54). What type of radioactive decay is this?

A) electron capture
B) electron ionization
C) beta decay
D) alpha decay

Question 35

Chemical analysis of a rock can tell us

A) when the rock formed
B) the detailed geological history of the rock
C) what the rock is made of
D) the temperature and pressure conditions under which it formed

Question 36

In electron capture,

A) a proton turns into a neutron
B) a helium nucleus is ejected
C) a proton turns into an electron
D) a neutron turns into a proton

Question 37

A fossil is found in a layer of strata below one layer dated at 8 million years. From this we can deduce the age of the fossil to be

A) between 7 and 8 million years old
B) we can tell nothing about the fossil's age from this data
C) older than 8 million years
D) younger than 7 million years

Question 38

When an igneous rock is melted and then re-solidifies it turns into

A) a meteorite
B) a sedimentary rock
C) another igneous rock
D) a metamorphic rock

Question 39

A radioactive isotope with an atomic number of 90 undergoes beta decay. What is the atomic number of the daughter nucleus?

A) 89
B) 91
C) 92
D) 88

Question 40

Isotopic analysis of a rock can tell us

A) what the rock is made of
B) the detailed geological history of the rock
C) the temperature and pressure conditions under which it formed
D) when the rock formed

Question 41

Which type or types of rock can be dated radiometrically?

A) igneous and metamorphic
B) all rocks can be dated radiometrically
C) metamorphic only
D) igneous only

Question 42

Although fossils can be made in numerous ways, only a tiny fraction of living organisms leave behind any kind of fossil remnant because

A) most minerals that replace organic material are soluble in water and so dissolve away
B) the vast majority of dead organisms decay long before any mineral replacement can occur
C) the organic material is destroyed by radioactivity
D) they are destroyed by geological processes before mineral replacement can occur

Question 43

The Earth's geological time scale is divided into four main

A) epochs
B) periods
C) eras
D) eons

Question 44

In which eon of Earth's history did the early bombardment occur?

A) Hadean
B) Archean
C) Phanerozoic
D) Proterozoic

Question 45

Which type of rock is the easiest to date radiometrically?

A) sedimentary
B) all three types of rock are equally easy to date
C) metamorphic
D) igneous

Question 46

Radiometric dating of a rock reveals an age of 1.52 billion years. Given that the half-life of the parent isotope used is 14.0 billion years, what percentage of the parent isotope is still present in the rock?

A) 92.8%
B) 10.9%
C) 76.4%
D) 7.26%

Question 47

If originally there were X atoms of radioactive isotope present and now there are only X/2 atoms, how many half-lives have elapsed?

A) 3
B) 1
C) 4
D) 2

Question 48

If originally there were X atoms of radioactive isotope present and now there are only X/16 atoms, how many half-lives have elapsed?

A) 4
B) 1
C) 2
D) 3

Question 49

Fossils of the earliest life are very difficult to identify in very old rocks because it

A) was very simple and microscopic in size
B) was not made of organic material that could be replaced by minerals
C) was so different to life found on Earth today that we are not capable of identifying it
D) did not leave behind any fossilized remains

Question 50

The Earth's geological history is divided into how many eons?

A) 4
B) 1
C) 3
D) 2

Question 51

At the beginning of which eon of Earth's history do we find the earliest evidence of life?

A) Phanerozoic
B) Proterozoic
C) Archean
D) Hadean

Question 52

A rock sample contains 1/2 microgram of the parent radioactive isotope Uranium-235 and 1/2 microgram of its daughter isotope Lead-207. If the half-life of this decay is 700 million years, how old is this rock?

A) 1400 million years
B) 2100 million years
C) 700 million years
D) 350 million years

Question 53

A rock sample contains 1/8 micrograms of the parent radioactive isotope Aluminum-26 and 7/8 micrograms of its daughter isotope Magnesium-40. If the half-life of this decay is approximately 700,000 years, how old is this rock?

A) 2.1 million years
B) 2.8 million years
C) 1.4 million years
D) 700,000 years

Question 54

You chemically analyze a small sample of a meteorite. K-40 and Ar-40 are present in a ratio of approximately 1.65 units of K-40 atoms to 8.35 units of gaseous Ar-40 atoms. How old is the meteorite given the half-life of this decay is 1.25 billion years?

A) 1.25 billion years
B) 5.00 billion years
C) 2.75 billion years
D) 3.25 billion years

Question 55

A rock sample contains 1/4 micrograms of the parent radioactive isotope Potassium-40 and 3/4 micrograms of its daughter isotope Argon-40. If the half-life of this decay is 1.25 billion years, how old is this rock?

A) 5.00 billion years
B) 3.75 billion years
C) 1.25 billion years
D) 2.50 billion years

Question 56

The geological record contains fewer older rocks than younger rocks because older rocks

A) are mostly found deep within the Earth
B) have been transformed by life processes that have occurred inside them
C) have been destroyed by geological processes such as plate tectonics and erosion
D) have been destroyed by recent meteorite impacts

Question 57

If originally there were X atoms of radioactive isotope present and now there are only X/4 atoms, how many half-lives have elapsed?

A) 1
B) 4
C) 2
D) 3

Question 58

If originally there were X atoms of radioactive isotope present and now there are only X/8 atoms, how many half-lives have elapsed?

A) 3
B) 1
C) 4
D) 2

Question 59

Which type or types of rock cannot be dated radiometrically?

A) igneous and metamorphic
B) sedimentary
C) metamorphic
D) igneous

Question 60

Fossils typically contain little or no organic matter because

A) the organic matter has been destroyed when the rock containing the fossil was melted deep within the Earth's crust
B) inorganic minerals have gradually replaced the organic matter over time
C) the organic matter has radioactively decayed into inorganic matter
D) ancient organisms contained little organic matter

Question 61

Evidence from the analysis of zircon crystals suggests that the Earth

A) may have been habitable immediately after its formation
B) could only have been habitable after significant amounts of oxygen had built up in its atmosphere
C) could only have been habitable after the end of the Hadean Eon 500 million years ago
D) may have been habitable as little as 100 million years after its formation

Question 62

During the Hadean Eon, life may

A) have existed but could not have survived for long periods due to frequent sterilizing impacts
B) have existed and survived living underground and in some deep ocean environments
C) have existed and survived in all environments
D) could not have existed at all

Question 63

In which eon of Earth's history did dinosaurs and mammals first appear?

A) Hadean
B) Archean
C) Phanerozoic
D) Proterozoic

Question 64

At the beginning of which eon of Earth's history did life originate?

A) Proterozoic
B) Phanerozoic
C) Archean
D) Hadean

Question 65

Isotopic analysis of meteorites suggests the Earth and the rest of the solar system formed

A) 3.85 billion years ago
B) 4.57 billion years ago
C) 4.4 billion years ago
D) 4.0 billion years ago

Question 66

Analysis of rocks returned from the lunar maria during the Apollo program suggest they formed

A) during the period of early bombardment constituting the first few hundred million years of the Earth's history
B) fairly recently during the last million years or so
C) roughly 65 million years ago
D) between 3.9 and 3.0 billion years ago

Question 67

The oldest intact rocks found on Earth date back to approximately

A) 4.5 billion years ago
B) 3.85 billion years ago
C) 3.5 billion years ago
D) 4.0 billion years ago

Question 68

Most of the craters on the highlands of the Moon were formed

A) approximately 65 million years ago
B) during the period of late bombardment around 3.9 billion years ago
C) fairly recently during the last million years or so
D) during the period of early bombardment constituting the first few hundred million years of the Earth's history

Question 69

In addition to outgassing by volcanoes, another important contributor to the formation the Earth's oceans and atmosphere was

A) impacts by icy planetesimals
B) material directly accreted from the Sun
C) material directly accreted from the solar nebula
D) melting and vaporization of polar glaciers

Question 70

The composition of the early atmosphere was dominated by

A) hydrogen (H₂)
B) nitrogen (N₂)
C) carbon dioxide (CO₂)
D) oxygen (O₂)

Question 71

Tiny grains of zirconium silicate (zircons) found embedded in sedimentary rocks have been radiometrically dated to what age?

A) 3.5 billion years ago
B) 3.85 billion years ago
C) 4.4 billion years ago
D) 4.0 billion years ago

Question 72

The Earth's crust appears to have already differentiated from the interior approximately

A) 3.85 billion years ago
B) 4.0 billion years ago
C) 4.4 billion years ago
D) 4.5 billion years ago

Question 73

During the Hadean Eon, large impact events were separated by periods of

A) a few years
B) several days
C) billions of years
D) thousands or millions of years

Question 74

What do we currently believe was the main source of the Earth's oceans and atmosphere?

A) impacts by icy planetesimals
B) outgassing by volcanoes
C) material directly accreted from the solar nebula
D) melting and vaporization of polar glaciers

Question 75

The dark maria on the moon are

A) layers of dark meteoritic debris from impacts
B) layers of darker rock just beneath the surface which have been uncovered by impacts
C) huge impact basins filled in by lava flows
D) oceans of liquid water covering the surface

Question 76

Given the Earth's larger size and strong gravity, the Earth's surface should have more impact craters than the Moon. However, it has very few. Why is this?

A) the Moon acted like a shield, protecting the Earth from most impacts
B) the Earth's surface was almost completely molten during the Hadean Eon so no impact craters were formed
C) almost all impacts occurred in the oceans so no impact craters were formed
D) geological processes like plate tectonics, volcanism, and weathering have erased them

Question 77

A sterilizing impact is one during which

A) all life on a planet is destroyed
B) all life on the surface of a planet is destroyed but life in the oceans or beneath the surface survives
C) a planet is fragmented into pieces
D) life on a planet is rendered incapable of reproduction

Question 78

Given that all bodies in the solar system should have suffered equally from collisions during the period of early bombardment, if we find a body with relatively few craters on its surface we deduce that

A) the surface of the body is made of material that produces fewer impact craters
B) the body must have been located in a region of the solar system that for some reason suffered fewer collisions
C) the body must have formed after the period of early bombardment
D) geological activity or other processes must have removed older craters resulting in a younger, smoother surface

Question 79

The Hadean Eon corresponds approximately to the

A) last 65 million years of Earth's history
B) last 540 million years of Earth's history
C) first 600 million years of Earth's history
D) first 2 billion years of Earth's history

Question 80

Planetary scientists use crater counts to estimate the

A) habitability of planetary surfaces
B) ages of planetary surfaces
C) temperatures of planetary surfaces
D) chemical compositions of planetary surfaces