Astronomy Chapter 8 Study Guide Test.
The age of the solar system can be established by radioactive dating of... - CORRECT ANSWER The oldest
meteorites
In essence, the nebular theory holds that: - CORRECT ANSWER our solar system formed from the
collapse of an interstellar cloud of gas and dust
Which of the following types of material can condense into what we call ice at low temperatures? -
CORRECT ANSWER Hydrogen compounds
What do we mean by the frost line when we discuss the formation of planets in the solar nebula? -
CORRECT ANSWER It is a circle at a particular distance from the Sun, beyond which the temperature was
low enough for ices to condense.
Suppose you start with 1 kilogram of a radioactive substance that has a half-life of 10 years. Which of
the following statements will be true after 20 years pass? - CORRECT ANSWER You'll have 0.25 kilogram
of the radioactive substance remaining.
What is the leading hypothesis for the origin of the Moon? - CORRECT ANSWER It formed from the
material ejected from Earth in a giant impact.
According to our theory of solar system formation, what three major changes occurred in the solar
nebula as it shrank in size? - CORRECT ANSWER It got hotter, its rate of rotation increased, and it
flattened into a disk.
Our solar system was created by the gravitational collapse of the __________. - CORRECT ANSWER solar
nebula
__________ allows us to determine the age of a solid rock. - CORRECT ANSWER Radiometric dating
Ice can form from a gas through the process of: - CORRECT ANSWER Condensation
, Mars was formed by the __________ of smaller objects. - CORRECT ANSWER accretion
Our Moon was most likely formed by a collision between Earth and a Mars-sized __________. -
CORRECT ANSWER planetesimal
The first few hundred million years of the solar system's history were the time of the __________,
during which Earth suffered many large impacts. - CORRECT ANSWER heavy bombardment
The era of planet formation ended when the remaining hydrogen and helium gas of the solar nebula
was swept into interstellar space by the __________. - CORRECT ANSWER solar wind
Hydrogen compounds in the solar system can condense into ices only beyond the __________. -
CORRECT ANSWER frost line
What law explains why cloud spins faster as it shrinks in size? - CORRECT ANSWER the law of
conservation of angular momentum
What law explains why the center of the cloud becomes so much hotter as the cloud shrinks in size? -
CORRECT ANSWER the law of conservation of energy
Significance of the meteorite? - CORRECT ANSWER The shiny metal flakes embedded in rock are just
what we expect if condensation really occurred as the nebular theory predicts.
Where did the elements heavier than hydrogen and helium come from? - CORRECT ANSWER They were
produced inside stars.
What percentage of the mass of the solar nebula consisted of elements other than hydrogen and
helium? - CORRECT ANSWER 2 percent
True or false: We have direct evidence from ALMA that supports nebular theory. - CORRECT ANSWER
True
The age of the solar system can be established by radioactive dating of... - CORRECT ANSWER The oldest
meteorites
In essence, the nebular theory holds that: - CORRECT ANSWER our solar system formed from the
collapse of an interstellar cloud of gas and dust
Which of the following types of material can condense into what we call ice at low temperatures? -
CORRECT ANSWER Hydrogen compounds
What do we mean by the frost line when we discuss the formation of planets in the solar nebula? -
CORRECT ANSWER It is a circle at a particular distance from the Sun, beyond which the temperature was
low enough for ices to condense.
Suppose you start with 1 kilogram of a radioactive substance that has a half-life of 10 years. Which of
the following statements will be true after 20 years pass? - CORRECT ANSWER You'll have 0.25 kilogram
of the radioactive substance remaining.
What is the leading hypothesis for the origin of the Moon? - CORRECT ANSWER It formed from the
material ejected from Earth in a giant impact.
According to our theory of solar system formation, what three major changes occurred in the solar
nebula as it shrank in size? - CORRECT ANSWER It got hotter, its rate of rotation increased, and it
flattened into a disk.
Our solar system was created by the gravitational collapse of the __________. - CORRECT ANSWER solar
nebula
__________ allows us to determine the age of a solid rock. - CORRECT ANSWER Radiometric dating
Ice can form from a gas through the process of: - CORRECT ANSWER Condensation
, Mars was formed by the __________ of smaller objects. - CORRECT ANSWER accretion
Our Moon was most likely formed by a collision between Earth and a Mars-sized __________. -
CORRECT ANSWER planetesimal
The first few hundred million years of the solar system's history were the time of the __________,
during which Earth suffered many large impacts. - CORRECT ANSWER heavy bombardment
The era of planet formation ended when the remaining hydrogen and helium gas of the solar nebula
was swept into interstellar space by the __________. - CORRECT ANSWER solar wind
Hydrogen compounds in the solar system can condense into ices only beyond the __________. -
CORRECT ANSWER frost line
What law explains why cloud spins faster as it shrinks in size? - CORRECT ANSWER the law of
conservation of angular momentum
What law explains why the center of the cloud becomes so much hotter as the cloud shrinks in size? -
CORRECT ANSWER the law of conservation of energy
Significance of the meteorite? - CORRECT ANSWER The shiny metal flakes embedded in rock are just
what we expect if condensation really occurred as the nebular theory predicts.
Where did the elements heavier than hydrogen and helium come from? - CORRECT ANSWER They were
produced inside stars.
What percentage of the mass of the solar nebula consisted of elements other than hydrogen and
helium? - CORRECT ANSWER 2 percent
True or false: We have direct evidence from ALMA that supports nebular theory. - CORRECT ANSWER
True
