1 Gamma rays have a small ______.
wavelength
2 Which of the following statements about X rays and radio waves is not true?
X rays travel through space faster than radio waves.
3When considering light as made up of individual "pieces," each characterized by a particular amount of energy, the pieces are called _________.
photons
4 Thermal radiation is defined as _________.
radiation with a spectrum whose shape depends only on the temperature of the emitting object
5 Which of the following conditions lead you to see an absorption line spectrum from a cloud of gas in interstellar space?
The cloud is cool and lies between you and a hot star.
6 Laboratory measurements show hydrogen produces a spectral line at a wavelength of 486.1 nanometers (nm). A particular star's spectrum shows the same hydrogen line at a wavelength of 486.0 nm. What can we conclude?
The star is moving toward us.
7 Studying a spectrum from a star can tell us a lot. All of the following statements are true except one. Which statement is not true?
The total amount of light in the spectrum tells us the star's radius.
8Consider an atom of carbon in which the nucleus contains 6 protons and 7 neutrons. What is its atomic number and atomic mass number?
atomic number = 6; atomic mass number = 13
9An atom that has fewer electrons than protons is called a/an _________.
ion
10 The spectra of most galaxies show redshifts. This means that their spectral lines _________.
have a higher intensity in the red part of the spectrum
11The light-collecting area of an 8-meter telescope is _____ times that of a 2-meter telescope.
16
12The Chandra X-ray Observatory must operate in space because:
X rays do not penetrate Earth's atmosphere.
13Astronomers have begun to build instruments to detect "cosmic messengers" that are not forms of light, such as neutrinos, cosmic rays, and gravitational waves, because they __________.
provide information about distant objects that we cannot obtain from light
14What do astronomers mean by light pollution?
Light pollution is light from human sources that makes it difficult to see the stars at night.
15The rate of wave peak travel through space is
speed
16The distance between two successive peaks in a wave is
wavelength
17The number of wave peaks passing by a point in a second is
frequency
18If light has a long wavelength, what can you say about its frequency?
Speed of wave is equal to the product of wavelength and frequency. As the speed of the light is constant, long wavelength means low frequency of light.
19An atom with more electrons than protons has a negative
electric charge
20The sum of the number of protons and neutrons in an atom is called the
atomic mass number
21Most hydrogen atoms have only a single proton in their nucleus, so a hydrogen atom that also has one neutron is an _____ of hydrogen
isotope
22The number of protons in an atom is called the atom's
atomic number
23Each chemical element has a unique
atomic number
24What is the correct composition of a neutral atom of helium-4?
2 protons, 2 neutrons, 2 electrons
25Which of the following type of spectrum would you expect if you view star light that has passed through a cool cloud of interstellar gas on its way to Earth?
an absorption line spectrum
26Rank from lowest to highest energy. To rank items as equivalent, overlap them.
Infared, ultraviolet, x rays, gamma rays, radio waves, visible
lowest to highest: radio, infared, visible, ultraviolet, x rays, gamma rays
27Is the order the same from lowest to highest frequency? from shortest to longest wavelength?
The ranking by frequency would have the same order, since energy is directly proportional to frequency. The ranking by wavelength would have the opposite order, because frequency and wavelength are inversely related.
28Radio waves are a form of
low-frequency light.
29Suppose you go outside and look at three stars. Star A is blue, Star B is white, and Star C is red. Which star is has the hottest surface temperature and which star has the coldest surface temperature?
Star A is the hottest and Star C is the coldest.
30Which object emits more total infrared radiation?
A star that is the same size as the Sun but with a hotter surface temperature
31Choose the correct definition of atomic number.
An atomic number is the number of protons an atom has in its nucleus.
32Choose the correct definition of atomic mass number.
An atomic mass number is the number of protons plus the number of neutrons.
33Choose the correct conditions, under which two atoms are different isotopes of the same element.
Two atoms having the same number of protons and different numbers of neutrons.
34Choose the correct definition of electrical charge.
Electrical charge is a measure of how strongly something will interact with electromagnetic fields.
35Will an electron and a proton attract or repel one another? How about two electrons?
We define a proton as having +1 unit of charge and an electron as having –1 unit when talking about atoms and particles. Two particles with charges of different sign will attract each other, so protons and electrons will attract. Particles with charges of the same sign will repel each other, so two electrons will repel each other.
36If a star is moving away from Earth, the absorption lines in its spectrum will have __________ the same lines measured at rest in the laboratory.
longer wavelengths (redshifts) than
37Consider a star that is moving away from us at a constant speed. How will the wavelengths of the absorption lines in its spectrum change as the star gets farther and farther away?
The wavelengths will remain the same regardless of the distance.
38If the emission lines in the spectrum of Object 1 have a larger blueshift than those of Object 2, then Object 1 is moving __________ than Object 2.
toward us faster
39If we calculate a star's speed (relative to Earth) from its Doppler shift alone, this is likely to be an __________ of the object's total speed.
underestimate
40For the radial speed (toward or away from us) of an astronomical object to be determined, it is important for the object’s spectrum to contain
either absorption or emission lines.
41If a hot gas cloud is moving across the sky but with no motion neither toward or away from us, its emission lines would be
neither blueshifted nor redshifted.
42If a hot gas cloud is moving toward us, the frequency of the emission lines will be __________ those of a stationary gas cloud.
higher than
43Compared to red light, blue light has higher frequency,
higher energy, and shorter wavelength.
44Compared to an atom as a whole, an atomic nucleus is
very tiny but has most of the mass.
45We see ____ spectrum when we look at a thin or low-density cloud of hot gas.
an emission line
46We see ___ spectrum when we look a dense hot object emitting light.
a continuous
47We see ___ spectrum when we look through a cloud of gas at a dense hot object emitting light.
an absorbtion line
48Which type is the Sun's spectrum, and why?
An absorption line spectrum over a continuous spectrum. Relatively thin photosphere of the Sun absorbs the specific wavelength from the light emitted from the hot and dense interior of the Sun.
49What are the two most important properties of a telescope?
light-collecting area
angular resolution
50How much more light does an 8-meter telescope gather than a 2-meter telescope?
16 times as much
51Suppose that two stars are separated in the sky by 0.01 arcsecond, and you observe them with a telescope that has an angular resolution of 1 arcsecond. What will you see?
The light from the two stars will be blended together so that they look like one star.
52A camera is an example of an instrument used for ___ observations
imaging
53____ refers to telescopic observations in which we separate an object's light so we can measure its intensity at different wavelengths.
spectrosocpy
54If we want to confirm that a star's brightness alternately dims and brightens, we need
______ observations of the star.
time monitoring
55The familiar twinkling of the stars is caused by ______, which also blurs telescopic images.
atmospheric turbulence
56Human civilization is responsible for what astronomers call
light pollution
57What is the primary reason that we launch X-ray telescopes into space rather than building them on the ground?
X-rays from space do not reach the ground.
58The set of spectral lines that we see in a star's spectrum depends on the star's:
chemical composition.
59A star whose spectrum peaks in the infrared is
сooler than our Sun.
60Which of the following forms of light can be observed with telescopes at sea level?
visible light
radio waves
61If our eyes were sensitive only to X rays, the world would appear __________.
dark because X-ray light does not reach Earth’s surface
62If you had only one telescope and wanted to take both visible-light and ultraviolet pictures of stars, where should you locate your telescope?
in space
63The James Webb Space Telescope is designed primarily to observe __________.
infrared light
64The Hubble Space Telescope obtains higher-resolution images than most ground-based telescopes because it is:
above Earth's atmosphere.
65What type of visible light spectrum does the Sun produce?
an absorption line spectrum
66Compared to the distance between Earth and Mars, the distance between Jupiter and Saturn is _________.
much larger
67Venus has a higher average surface temperature than Mercury. Why?
Because its surface is heated by an extreme greenhouse effect.
68Which of the following lists the planets of our solar system in the correct order from closest to farthest from the Sun?
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
69 Suppose you view the solar system from high above Earth's North Pole. Which of the following statements about planetary orbits will be true?
All the planets orbit counterclockwise around the Sun.
70Which of the following statements about our Sun is not true?
The Sun's diameter is about 5 times that of Earth.
71 Which of the following is not a major difference between the terrestrial and jovian planets in our solar system?
Terrestrial planets actually contain very little ice, because they are made mostly of metal and rock.
72 What is the primary basis on which we divide the ingredients of the solar nebula into the four categories hydrogen/helium, hydrogen compounds, rock, and metal?
The temperatures at which various materials can condense from gaseous form to solid form.
73 In essence, the nebular theory holds that _________.
our solar system formed from the collapse of an interstellar cloud of gas and dust
74 According to our theory of solar system formation, what three major changes occurred in the solar nebula as it shrank in size?
It got hotter, its rate of rotation increased, and it flattened into a disk.
75 In the context of the formation of planets in the solar nebula, the frost line marks the distance from the Sun beyond which _________.
the temperature was low enough for hydrogen compounds to condense into ices
76 What do we mean by accretion in the context of planet formation?
The growth of planetesimals from smaller solid particles that collided and stuck together
77What is the giant impact hypothesis for the origin of the Moon?
The Moon formed from material blasted out of the Earth's mantle and crust by the impact of a Mars-size object.
78 According to modern scientific dating techniques, approximately how long ago did Earth and the other planets of our solar system form?
4.5 billion years
79What's unusual about our Moon?
It’s surprisingly large relative to the planet it orbits.
80Are there any exceptions to the rule that planets rotate with small axis tilts and in the same direction that they orbit the Sun?
Venus and Uranus are exceptions.
81What are four key features of our solar system that any theory of solar system formation must be able to explain?
There are a few notable “exceptions to the rules.”
There are clear patterns to the rotation and orbits of large bodies in the solar system.
Planets fall into two major categories.
There are vast numbers of asteroids and comets.
82We expect a scientific theory to be able to make predictions that can be tested. Which of the following is a prediction of the nebular theory that has been verified by observations?
Many stars should have planets.
83The "giant impact hypothesis" refers to the idea that ___________.
our Moon formed when a Mars-size object collided with the young Earth.
84Based on current scientific evidence, the planets in our solar system are thought to have
formed in the same gas cloud and about the same time that the Sun formed.
85As the solar nebula collapsed, it became a disk because
collisions between particles tended to make the particles orbit in mostly the same direction.
86Our current theory of solar system formation suggests that the inner planets are small and rocky and the outer planets are mostly large and gaseous because of differences in ___________ between the inner and outer regions of the solar nebula at the time the planets formed.
temperature
87Which of the following correctly describes the way in which condensation occurred in the solar nebula?
Only rock and metal could condense in the inner solar system, while rock, metal, and hydrogen compounds could condense in the outer solar system.
88As the solar nebula collapsed under its own gravity,
it heated up and rotated faster.
89Which of the following is thought to have ended the formation of the planets?
The solar wind cleared away remaining gas and dust.
90Suppose the solar nebula initially had exactly zero angular momentum. In that case,
if they existed at all, the planets would not all orbit in the same plane.
91Suppose the solar nebula had been too warm for any hydrogen compounds to condense into ice anywhere. If a planet had still formed at Jupiter's location, it most likely would have
been similar in composition to Earth, with a much smaller mass than that of the real Jupiter.
92Which lists the major steps of solar system formation in the correct order?
collapse, condensation, accretion
93How many of the planets orbit the Sun in the same direction that Earth does?
all
94What is Jupiter's main ingredient?
hydrogen and helium
95What substances were found in the innermost regions (within about the inner 0.3 AU
) of the solar system before planets began to form?
rocks, metals, hydrogen compounds, hydrogen, and helium, all in gaseous form
96What substances existed as solid flakes within the innermost regions (within about the inner 0.3 AU
) of the solar system before planets began to form?
none
97Where would you expect terrestrial planets to form in the solar nebula?
anywhere between the innermost regions (within about the inner 0.3 AU
) and the frost line
98The jovian planets are thought to have formed as gravity drew hydrogen and helium gas around planetesimals made of __________.
rocks, metals, and ices
99The nebular theory also predicts that the cloud should heat up as it collapses. What physical law explains why it heats up?
the law of conservation of energy
100Leftover ice-rich planetesimals are called
comets
101The cores of the terrestrial worlds are made mostly of metal because ______.
metals sunk to the centers a long time ago when the interiors were molten throughout
102Scientists suspect that Mars once had a global magnetic field. Assuming this is true, which of the following could explain why Mars today lacks a global magnetic field like that of Earth?
Mars's interior has cooled so much its molten core layer no longer undergoes convection.
103 What are the two geological features that appear to set Earth apart from other terrestrial worlds in our solar system?
plate tectonics and a high level of erosion
104 Which of the following best describes how the greenhouse effect works?
A planet's surface absorbs visible sunlight and returns this absorbed energy to space as infrared light. Greenhouse gases slow the escape of this infrared radiation, which thereby heats the lower atmosphere.
105What do we mean when we say that the terrestrial worlds underwent differentiation?
When their interiors were molten, denser materials sank toward their centers and lighter materials rose toward their surfaces.
106The processes responsible for virtually all surface geology are _________.
impact cratering, volcanisms, tectonics, and erosion
107 Most of the Moon's surface is densely covered with craters, but we find relatively few craters within the lunar maria. What can we conclude?
The maria formed after the heavy bombardment ended.
108Which of the following is not a key line of evidence supporting the hypothesis that Mars once had abundant liquid water on its surface?
the canals of Mars mapped by Percival Lowell
109Why does Earth have so little carbon dioxide in its atmosphere compared to Venus?
Earth has just as much carbon dioxide as Venus, but most of it is locked up in carbonate rocks rather than being free in the atmosphere.
110What is the importance of the carbon dioxide (CO2) cycle?
It regulates the carbon dioxide concentration of our atmosphere, keeping temperatures moderate.
111The existence of a core-mantle-crust interior structure tells us that a world __________.
once had a molten interior
112How does the amount of heat released in a planet’s interior by radioactive decay change with time?
It drops off with time.
113As a general rule, smaller planets __________ than larger planets.
cool more rapidly
114Earth has a relatively strong magnetic field, but Mars does not. Which of the following probably explains why Mars lacks a strong magnetic field today?
Its core is too cool for convection.
115What is the longest-lasting internal heat source responsible for geological activity?
radioactive decay
116If we found an Earth-sized planet orbiting a Sun-like star at about half Earth's distance from the Sun, which planet of our solar system would we expect its surface to resemble the most?
Venus
117Suppose Mars had its current orbit but was only the size of Mercury (instead of its actual size). Which of the following would we expect to see on its surface (compared to the actual surface of Mars)?
Similar numbers of impact craters, but fewer volcanoes and tectonic valleys, and no erosion features
118Why don't we find as many impact craters on Earth as on the Moon?
Most of Earth's craters have been erased by volcanism, tectonic activity, and erosion.
119Which of the following would cause Venus's surface geology to look the most different from the way it looks today?
Make Venus half its current size.
120If Earth's diameter were half its actual size, which planet would we expect its surface to resemble the most?
Mars
121Greenhouse gases in the atmosphere, such as carbon dioxide and water vapor, make Earth warmer than it would be otherwise because these gases __________.
absorb infrared light emitted by the surface
122According to scientists, the naturally occurring greenhouse effect makes Earth about 31 ∘C
warmer than it would be if there were no greenhouse gases in our atmosphere. How do scientists "know" what Earth's temperature would be without greenhouse gases?
They calculate this temperature from Earth's reflectivity and distance from the Sun.
123On a cloudless day, what happens to most of the visible light headed toward Earth?
It reaches Earth’s surface, where some is reflected and some is absorbed.
124The greenhouse effect raises Earth’s surface temperature (from what it would be otherwise) because the infrared light radiated by Earth’s surface __________.
is absorbed by greenhouse gases, slowing the escape of this energy to space
125What happens to the energy that the ground absorbs in the form of visible sunlight?
It is returned upward in the form of infrared light.
126The oxygen in Earth’s atmosphere was released by
life
127Where is most of the CO2
that has outgassed from Earth's volcanoes?
locked into rocks
128Assuming that features you see on Mars are similar to features found on Earth, what would a casual inspection of the interactive photo of Mars lead you to suspect about water on Mars?
Surface water only exists as frozen ice.
129Which of the following Mars surface features provides dramatic evidence that volcanism has played a role in shaping the surface of Mars?
Olympus Mons
130Go to the screen in the interactive figure called "Key Evidence of Water," then zoom in on the “Southern Highlands.” Which geologic processes are most clearly evident in the southern highlands?
impact cratering and erosion
131According to current models of solar system formation, why did Uranus and Neptune end up to be much less massive than Jupiter and Saturn?
Particles in the solar nebula were more spread out at greater distances, so that accretion took longer and there was less time to pull in gas before the solar wind cleared the nebula.
132Why does Jupiter have three distinct layers of clouds?
The three layers represent clouds made of gases that condense at different temperatures.
133Uranus and Neptune have methane clouds but Jupiter and Saturn do not. Which factor explains why?
Temperatures on Jupiter and Saturn are too high for methane to condense.
134Which jovian planet has the most extreme seasonal changes, and why?
Uranus, because of its extreme axis tilt
135Which of the following is a general characteristic of the four jovian planets in our solar system?
They are significantly lower in average density than are the terrestrial planets.
136Overall, Jupiter's composition is most like that of _________.
the Sun
137Jupiter's colors come in part from its three layers of clouds. Which of the following is not the primary constituent of one of Jupiter's cloud layers?
clouds of sulfuric acid
138What atmospheric constituent is responsible for the blue color of Uranus and Neptune?
methane
139Which of the following is a key factor in explaining why many jovian moons have been more geologically active than the Moon or Mercury?
Jovian moons contain much more ice that can melt or deform at lower temperatures than can the rock and metal that make up the Moon and Mercury.
140 All the following statements are true. Which one is most important in explaining the tremendous tidal heating that occurs on Io?
Io orbits Jupiter on an elliptical orbit as a result of orbital resonances with other moons.
141What major feature of Saturn's moon Enceladus led scientists to suspect it might have a subsurface ocean?
fountains of ice spraying out from the surface into space
142What key evidence suggests that Triton is a captured moon?
Triton orbits Neptune in a direction opposite that of Neptune's rotation.
143Which of the following statements about the moons of the jovian planets is true?
Most of the moons have the potato-like shapes of asteroids, but a few are large enough to be spherical in shape.
144Which statement about Jupiter’s moon Io is true?
It is the most volcanically active body in our solar system.
145 What is tidal heating?
a source of internal heat caused by varying tidal forces acting on a moon or other object
146Which moon has a thick atmosphere made mostly of nitrogen?
Titan
147How do typical wind speeds in Jupiter's atmosphere compare to typical wind speeds on Earth?
They are much faster than hurricane winds on Earth.
148Which lists the jovian planets in order of increasing distance from the Sun?
Jupiter, Saturn, Uranus, Neptune
149The two jovian planets that contain the highest proportions of hydrogen compounds are ___________.
Uranus and Neptune
150Which of the following best describes the nature of planetary rings?
They are composed of countless individual particles.
151Why does Neptune appear blue and Jupiter red?
Methane in Neptune's atmosphere absorbs red light.
152Some jovian planets give off more energy than they receive because of
ongoing contraction or differentiation.
153The main ingredients of most moons of the jovian planets are
hydrogen compound ices.
154Io experiences tidal heating primarily because __________.
its elliptical orbit causes the tidal force to vary as Io orbits Jupiter.
155Why is Io more volcanically active than our moon?
Io has a different internal heat source.
156What is unusual about Triton?
It orbits its planet backward.
1571. The largest moon in the solar system is
ganyemede
1582. The jovian moon with the most geologically active surface is
lo
1593. Strong evidence both from surface features and magnetic field data support the existence of a subsurface ocean on
europa
160is responsible for the tremendous volcanic activity on Io.
tidal heating
161is the most distant of Jupiter's four Galilean moons.
callisto
1626. The fact that Europa orbits Jupiter twice for every one orbit of Ganymede is an example of a(n)
orbital resonance
163Planetary rings are made up of countless small particles composed of
ice and dust
164All rings lie in the ______ . Rings' particles have ________
equitorial plane of their planets | nearly cirlce
165's rings are the brightest and widest among jovian planets. Their particles consist most of
staturns | ice
166's rings are mostly dusty and less visible.
jupiter
167 both have narrow bright rings diveded by very sparse dusty rings in between.
Uranus and Neptune
168's narrow rings show irregularities in form of brighter arcs, as if the rings were incomplete or partial.
neptunes
169Saturn’s rings are composed of __________.
lots of individual particles of ice and rock
170Saturn’s rings look bright because __________.
light from the Sun reflects off the material in the rings
171Which of the following statements correctly describes the motion of the particles in Saturn’s rings?
Particles in the inner rings orbit Saturn at a faster speed than particles in the outer rings.
172When you see the bright flash of a meteor, what are you actually seeing?
the glow of heated air surrounding a small particle as it burns up in our atmosphere
173Which of the following best describes the primary difference between asteroids and comets?
Asteroids are rocky and comets are ice-rich.
174What is Eris?
an icy object that orbits in the Kuiper belt and is more massive than Pluto
175A rock found on Earth that crashed down from space is called a(n) ______.
meteorite
176Which statement about asteroids is not true?
If we could put all the asteroids together, they would make an object about the size of Earth.
177The asteroid belt is located _________.
between the orbits of Mars and Jupiter
178What do we mean by a primitive meteorite?
a meteorite that is essentially unchanged since it first condensed and accreted in the solar nebula almost 4.6 billion years ago
179Among discovered meteorites, we have found some with all the following origins except _________.
being a fragment from Comet Halley
180Which statement is not thought to be true of all comets in our solar system?
Comets always have tails.
181Comets with orbits that take them through the inner solar system shed sand- to pebble-size particles that then follow the comet around its orbit. How do these particles affect Earth?
They are the particles that produce meteor showers.
182According to current evidence, Pluto is best described as ______.
a large member of the Kuiper belt
183 If the hypothesis tracing the extinction of the dinosaurs to an impact is correct, the dinosaurs died off largely because ______.
of global climate effects initiated by dust and smoke that entered the atmosphere after the impact