Animations about Blackbody Radiation
Concept Map about Earth's Atmosphere
Concept Map about Venus' Atmosphere
Thought Questions from first Midterm
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Light Atoms Planet Atmospheres |
Blackbody Radiation Jovian Planets |
Types of Spectrum Terrestial Planet Geology Formation of the Solar System |
What is the meaning of the pictured experiment?

If the light hitting the prism goes through a red filter first, what will you end up seeing on the screen?
A person's clothes appear dark blue when the fluorescent lights (white light) are on. How will the person's clothes appear when the street lamp (which emits pure yellow light) is on?
A person's clothes appear dark red when the fluorescent lights (white light) are on. How will the person's clothes appear when the street lamp (which emits pure yellow light) is on?
If you look at a blue dot on the screen through a red filter, what will you see?
If you look at a red dot on the screen through a blue filter, what will you see?
Compared to other colors of visible light, red light has
If you removed the green and orange light coming from an object that is releasing the mixture below, what would the spectrum look like?
Answer: A. Hint: Green and orange are kinds of light on their
own.
Which of the following spectrums represents the light from red and
blue TV dots?
Answer: D. Hint: A red dot on your TV screen don't exclusively
release red light, but it does mostly release light near red in
wavelength.
Which of the following is true?
At a particular temperature, the light bulb appears orangish in color if you
look at it with only your eye. What color has to be added in large
amounts to get it to appear whiter?
As I increase the temperature of the light bulb filament, one student
watches the the color blue in the rainbow, while another student
watches the color red. What will the two students see?
Which color will become visible last as the temperature of the light bulb
filament is increased?
Police are following a suspect at night in San Diego using an infrared
camera. If the suspect jumps into the harbor, what will be seen on the
camera?
Using the graph below, which of the following best describes how star A compares to star B?
The graph below shows the blackbody spectra for three different
stars. Which of the stars has the reddest peak wavelength?
The graph below shows the blackbody spectra for three different
stars. Which of the stars has the highest temperature?
In the graph below, which of the statements best describes how star A appears in comparison to star B?
Stars A and C sit at the same distance from you. According to the
graph below, which of these statements is true?
The Sun appears to have a yellow-white color to our naked eyes. If you
were to look at another star that was hotter than the Sun, which of
the following tints could it be?
Two stars have the same size, but different surface temperatures:
one has a temperature equal to that of the Sun (about 5800 degrees
Kelvin), while the other has a temperature twice that. Which of
the following is NOT true?
When I pass the jug of clear blue liquid in front of the light bulb,
what will you see in the spectrum?
Which of the following patterns most closely correponds to the pattern
of lines you saw in the spectrum in class?
Answer: D. Hint: I include this question just to remind you
that the pattern of lines can be used to uniquely identify the
chemical creating the lines. (This spectrum was for hydrogen gas.)
Imagine that you are on the surface of Earth (below the atmosphere)
and are observing the Sun. What kind of spectrum would you observe by
analyzing the sunlight?
Imagine that you are on looking at two different spectra of the Sun.
Spectrum number #1 is obtained using a telescope in orbit high above
Earth's atmosphere. Spectrum #2 is obtained using a telescope on
Earth. Which spectrum comes from the telescope on Earth (#2)?
Answer: Bottom. Hint: Earth's atmosphere absorbs some of the
sunlight passing through it, adding new lines to the spectrum.
Imagine that white light is falling on your red shirt. If you took a
spectrum of the light reflecting off your shirt, what would you
see?
The electrical force attracts an electron to a proton. To move an
electron from a low orbit to a high orbit (farther from the proton),
what has to happen?
A green photon must be absorbed to get an electron to move from the
ground state to an excited state (a larger orbit). To get the electron
to move to a higher excited state (an even larger orbit), what kind of
photon might the electron be able to absorb?
An atom has energy levels with energies of 0, 3, and 5 units. The
energy level with an energy of 5 units is the outermost boundary of
the atom. Assuming this atom has a single electron in the ``0'' energy
level (the ground state), which of the following photon energies can
the electron absorb to move it to another orbit?
An atom has energy levels with energies of 0, 3, 9, and 10 units. The
energy level with an energy of 10 units is the outermost boundary of
the atom. Assuming this atom has a single electron in the ``3'' energy level,
which of the following photon energies can the electron absorb? (There are
two correct answers.)
Atom X has energy levels with energies of 0 and 10 units. Atom Y has energy
levels with energies of 0 and 12 units. In each atom, an electron moves from
the upper energy level to the lower energy level, emitting a single photon
in the process. Which of the photons has longer wavelength?
What happens to the crust where extension occurs?
Imagine an impact occurred on the continental plate millions and
millions of years ago, leaving a crater near the base
of the volcano. Why would there be little evidence of this crater
found today?
In the image below, how heavily covered with craters is Mars?
Is there a relationship between the number of craters and either the
distance of the planet from the Sun or the size of the planet?
Imagine the pictures below were taken of an area of the Moon with craters at
various times in the past. What is the correct order of the pictures from
past to present?
The dark grey area is one of the Moon's maria. How old is the
lava in it compared to the other craters?
In the picture of Mars' surface below, there are several overlapping
features. ``A'' is a volcano, ``B'' and ``C'' are craters, and ``D''
is the surface of the flat plain that surrounds everything. Keeping in
mind that the surface of the plain {\it might} have been covered up by
lava from another volcano, which is the correct order of their ages
(from oldest to youngest)?
In the picture of Mars' surface below, which is older?
In the picture of Mars' surface below, "A" is the set of gullies, "B"
is the crater and splashed rock on the right side, and "C" is the
crater at the top. What is the order from oldest to youngest?
In the picture of Venus' surface below, "1" is the set of long cracks
(from tectonics), and "2" and "3" are lava domes. What is the order
from oldest to youngest?
Is there a relationship between the number of volcanoes and either the
distance of the planet from the Sun or the size of the planet?
Suppose a terrestrial planet the same age as Earth is discovered
orbiting another star, and it is your job to predict what it
is like. If the planet is known to have mass and size smaller than
Venus, but more than Mars, what would be the best prediction based on
our understanding of the solar system?
What gas in Earth's atmosphere is suspected of causing global warming?
Earth emits a continuous spectrum of light because it is a
dense, opaque object with a temperature. Earth's average temperature
is similar to that of a human being. What kind of light does Earth
emit the most of?
What would happen to Earth's temperature if Earth were more reflective?
What might Mars have been like if it had had a mass and size more like
Venus and Earth?
The temperature of the parts of Jupiter's atmosphere that we can see
from space is around -200 degrees F. What would we see if we look at
the visible light portion of Jupiter's spectrum?
Below is a picture of Saturn's moon Enceladus. Which of the following
statements about its surface is probably true?
You just bought what your jeweler said was a solid gold ring, but you
don't trust the jeweler. You measure the mass on a scale and find it
to be 10 grams. You measure the volume by dropping it in a full glass
of water and measuring how much water spills out. You find out that
the volume of the ring is 1.2 cubic centimeters. Which of the following is
true?
A planet discovered orbiting another star was found to have a mass
that is 0.7 times Jupiter's mass, and a size that is 1.4 times
Jupiter's size (so that its volume is 2.7 times greater than
Jupiter's). Which of the following is true?
What will happen if he moves his arms up and down, parallel to his
spin axis?
What would happen to a cloud that collapsed without any rotation at
all?
What kind of material would you expect to be able to condense out
of the gas closest to the Sun?
We believe that the denser planets tend to be located nearer the Sun
because
Which of the following statements describes the meaning of
condensation?
Which of the following pairs of planets formed at temperatures below
the freezing point of water?
Would it have been possible for a large Jupiter-like planet to form in
the location of Mars?
As more and more planetesimals get stuck together, new collisions will
occur
Which of these facts is NOT explained by nebular theory?
J. P. Adams, D. J. Loranz, E. E. Prather, and
T. F. Slater. Lecture Tutorials for Introductory Astronomy --
Instructor's Guide, 2002 (Prentice Hall).
Number of accesses:
Last update: October 30, 2007
Answer: 4. Hint: How do energy, wavelength, and frequency
relate to each other?
Blackbody Radiation
If you watch the light bulb with only your eyes, what is going to
happen to the light bulb filament as I increase its temperature?
Answer: 1. Hint: The light bulb filament is a blackbody.
As the temperature increases, both the color and brightness of the
filament change. REMEMBER: "red hot" is NOT hotter than "white
hot"!!!
Answer: 3. Hint: "White light" is a roughly equal mixture of
all of the colors of the rainbow. If the filament appears orange,
there is more red, orange, and yellow than there is green and blue.
Answer: 1. Hint: Photons of light are released during every
collision between atoms in the filament. The higher the temperature,
the more collisions occur. Every collision results in a release of light.
Answer: 6. Hint: As the temperature increases, collisions
become more violent (and more energetic) because the atoms are
travelling faster. Photons with a lot of energy can only be created
during the violent collisions.
Answer: 4. Hint: Normally humans release a lot of infrared light
because of their temperatures. When the suspect jumps in the cold San Diego
water, his skin immediately cools off and makes him "dim".
Answer: 1. Hint: Find the wavelength with the color red. Notice
that the curve for star A falls higher than the cure for star B,
meaning star A releases more red light. Just because red is the
brightest color for star B DOES NOT mean that it must be the brightest
star in red light!
Answer: 3. Hint: By "reddest peak wavelength", we mean the
one that has the peak with the largest wavelength (most to the right).
Answer: 1. Hint: Hot objects have short peak wavelength
(most to the left), which makes them appear to have a bluer tint.
Answer: 4. Hint: Star A is releasing much more blue light than
red light, which makes it appear blue. Star B is the opposite - it
will appear reddish.
Answer: 2. Hint: Both stars are the same temperature (their
peaks are at the same wavelength), but star A is brighter. Star A must
be larger (more surface to release light).
Answer: 4. Hint: As the temperature increases, what colors become
most intense?
Answer: 4. Hint: A blackbody gets brighter as its temperature
increases, and it emits more light at all wavelengths. However,
the color of the most intense light becomes bluer (shorter
wavelength).
Types of Spectrum
I have a jug of clear blue liquid. Which of the following is true?
Answer: 2. Hint: The jug is not hot, so it is not emitting
visible light. The fact that you see it is blue means that blue light
(and similar colors) is reaching your eyes.
Answer: 4. Hint: The jug is not hot, so it is not emitting
visible light. It is transparent. The fact that you see it is blue
means that blue light is reaching your eyes. So in this case, some of
the orange and yellow light is likely to be removed from the mixture
of light coming from the light bulb.
Answer: 3. Hint: Light from a hot opaque object (the Sun) is
passing through a cool gas (Earth's atmosphere). This is Kirchoff's
third law.
Answer: 1. Hint: The red you see is light reflected from the clothes.
Other colors (like blue) would be absorbed by the chemical dyes in the
shirt.
Atoms
Why do electrons move around the nucleus of the atom?
Answer: 2. Hint: Just like a satellite in orbit, there must
be a net acting on the electron to have it move in a curved path
(Newton's first law of motion).
Answer: 1. Hint: The electrical force attracts the electron to
the nucleus and holds it in its orbit, so effort has to be spent to
move the electron away.
Answer: 3. Hint: The farther the electron is moved away from the
nucleus, the more energy is needed. Blue photons have more energy that
red or green photons.
Answer: 3. Hint: Absorbing 3 units of energy would get the
electron to first excited state from the ground state. Absorbing 5 units
get the electron to the second excited state from the ground state.
Answer: 3 or 4. Hint: Absorbing 6 units of energy would get the
electron to the energy level having an energy of 9 units. Aborbing 8 units
would give the electron enough energy to get past the energy level having
10 units, which means the electron could be removed ("ionization").
Answer: 1. Hint: A photon of long wavelength has relatively
little energy.
Terrestrial Planet Geology
Mountain ranges form where plates are
Answer: 1. Hint: When the plates run into each other, one plate
"crumples" and forms mountains as the other plate slides under.
Answer: 3. Hint: In this case, the crust is stretched out, and
when it "tears" it forms cracks and valleys.
Answer: 3. Hint: Volcanoes sit on continental plates that
don't get melted during plate tectonics, but they do put out a
lot of lava...
Answer: 3. Hint: This is mostly a test of your skills at
observing. The northern hemisphere of Mars has very few craters
compared to the southern hemisphere - possibly because there was once
an ocean in the north.
Answer: 4. Hint: This may not seem to make sense, but the
larger planets definitely have fewer craters. Some reasons: their atmospheres
help melt smaller space rocks before they hit the surface, water erosion can
erase some craters, and volcanic activity or tectronics
can cover them up or completely destroy them.
Answer: 4. Hint: Craters that overlap help: the one on the
"bottom" must have been there the longest. The total number of craters
also helps: more creaters means that it has been longer since something
has "cleaned" the surface.
Answer: 3. Hint: Again, the idea of "overlapping" helps tell
which feature was laid down most recently.
Answer: 5. Hint: Look carefully at what overlaps what. Volcano
"A" must be oldest because everything overlaps it. Crater "C" has
obliterated part of "A" put has been filled in by the lava flow that
formed the plain "D". "D" has covered over the lower parts of "A".
The crater "B" overlaps both the "A" and "D", so it must be youngest.

Answer: 1. Hint: It appears as if some runoff water broke
through the side of the crater, and left some mud on the floor of the
crater.
Answer: 5. Hint: The crater at top is overwritten by gullies, and the crater at the side has covered up some of the gullies.
Answer: 3. Hint: Look at how the two lava domes over lap each
other, and how the cracks cut through the domes.
Answer: 3. Hint: Smaller planets cool off faster because they
don't insulate themselves well. The example I used in class was
comparing a cooked meatball and a cooked turkey. The inside of a
turkey can stay hot hours after it has been taken out of the oven.
Answer: 2. Hint: Mars has dormant volcanoes. Venus has a fairly
large number of active ones (astronomers think). Without knowing
exactly how massive this new planet is, we won't be able to predict
with any confidence whether the volcanoes are active or not.
Planet Atmospheres
When light from the Sun passes through the gas in a planet's atmosphere,
what happens?
Answer: 1. Hint: Some of the light passing through the
atmosphere gets absorbed. See earlier thought questions on light.
Answer: 3. Hint: Carbon dioxide is the only gas in the
atmosphere of Venus, and look what happened with it...
Answer: 2. Hint: The visible light that comes from the Earth is
reflected sunlight - Earth does not release visible light on its own
because it is not hot enough. Cooler blackbodies release longer
wavelength light... like infrared.
Answer: 2. Hint: Less energy would get absorbed by Earth, so
that it wouldn't warm up as much. This partly why people worry about
the melting of the polar ice caps with respect to global warming.
Answer: 4. Hint: Compare what Venus and Earth are like: they
both appear to have active volcanoes, and relatively thick
atmospheres. Because Mars would still be cooler than Earth (since it
is farther away from the Sun), it probably would have been able to
keep more water, although in the form of ice.
Answer: 3. Hint: The planet is colder than a person, so it
can't be emitting visible light. It can absorb some of the Sun's light,
while it reflects the rest.
Jovian Planets
Neptune is a deep blue color. Which of the following could be a reason
for this?
Answer: 4. Hint: Neptune is too cold to release any visible light -
what we see is reflected sunlight, which is white. So, for it to appear blue,
it has to remove the red light from the mix of light.
Answer: 3. Hint: Notice the lack of craters in the lower left.
Answer: 2. Hint: The average density (total mass divided by
total volume) is less than 10 grams per cubic centimeter. The density
of pure gold is about 19 grams per cubic centimeter.
Answer: 2. Hint: The planet has less mass than Jupiter, and it
is spread out over a larger volume, so that its average density must
be less than Jupiter's. This makes its average density even less like
a terrestrial planet (which has higher density).
Formation of the Solar System
If your daring professor sits in the ``CHAIR OF DEATH'' with his arms
outstretched and starts himself rotating, what will happen if he
pulls his arms in toward his body?
Answer: 3. Hint: If you have ever watched ice skaters, this
should be easy.
Answer: 2. Hint: A little harder, but again it comes from watching
ice skaters.
Answer: 1. Hint: With rotation, the collapsing gas can start to
orbit the Sun once it starts moving fast enough (like an ice skater pulling
in her arms).
Answer: 3. Hint: Which of the substances above melts at the highest
temperature? Rocky materials are a close second.
Answer: 3. Hint: The density of a planet does not affect how
strong the gravity is - remember that it just depends on mass. Rock
and metal was the only solid raw material available for the
terrestrial planets because of the high temperature.
Answer: 4. Hint: When water condenses on your soda
bottle, what is happening?
Answer: 5. Hint: Jupiter and Saturn got so big because they had
more raw material to start with --- namely, hydrogen compounds like water
that could condense into icy material.
Answer: 2. Hint: Was the temperature at the location of Mars
hotter or colder than the freezing point of water in the early solar
system?
Answer: 3. Hint: As the planetesimals collide and stick, there
are fewer objects left to collide. It gets harder for them to bump
into each other because there is more space between them.
Answer: 4. Hint: The number of planets depends on chance ---
there could have been more or less depending on how many collisions
there were during the formation of the solar system.
Some of the questions above are taken from the following
sources: