Question 1

The energy levels of an element and its ion are the same.

Accepted Answer

A) True 
 B)False

Question 2

The following questions refer to the diagram below. The levels represent energy levels in a hydrogen atom. Each level is labeled with its energy (above the ground state of Level 1) in units of electron/volts (eV). The labeled transitions represent an electron moving between energy levels.
 
-Which transition represents an electron that is breaking free of the atom?

Accepted Answer

The answer of The following questions refer to the diagram...

Question 3

The diagram represents energy levels in a hydrogen atom. The labeled transitions (A through E. represent an electron moving between energy levels. Suppose that an electron in a hydrogen atom absorbs 10.2 eV of energy, so that it moves from level 1 to level 2. What typically happens next?

Accepted Answer

A)  The electron returns to level 1 by emitting an ultraviolet photon with 10.2 eV of energy. 
B)  The electron jumps to level 3 as soon as it absorbs any additional energy. 
C)  The electron remains in level 2 until it absorbs an additional 10.2 eV of energy. 
D)  A different electron drops into level 1, since it is now unoccupied. 
A)  The electron returns to level 1 by emitting an ultraviolet photon with 10.2 eV of energy. 
B)  The electron jumps to level 3 as soon as it absorbs any additional energy. 
C)  The electron remains in level 2 until it absorbs an additional 10.2 eV of energy. 
D)  A different electron drops into level 1, since it is now unoccupied.

Question 4

If a hydrogen emission line appears at 656.2 nm in the laboratory, what can we say about a cloud of hydrogen gas, with an emission line at 680.2 nm?

Accepted Answer

A)  It is receding away from us. 
B)  The location of the emission line has nothing to do with speed. 
C)  It is neither receding nor approaching us. 
D)  It is approaching us. 
A)  It is receding away from us. 
B)  The location of the emission line has nothing to do with speed. 
C)  It is neither receding nor approaching us. 
D)  It is approaching us.

Question 5

Which of the following would be the most capable ultraviolet telescope?

Accepted Answer

A)  A 4 meter telescope, in space 
B)  A 30 meter telescope, on a mountain 
C)  A 2.5 meter telescope, in space 
D)  A 10 meter telescope, on a mountain 
A)  A 4 meter telescope, in space 
B)  A 30 meter telescope, on a mountain 
C)  A 2.5 meter telescope, in space 
D)  A 10 meter telescope, on a mountain

Question 6

From laboratory measurements, we know that a particular spectral line formed by hydrogen appears at a wavelength of 121.6 nanometers (nm). The spectrum of a particular star shows the same hydrogen line appearing at a wavelength of 121.8 nm. What can we conclude?

Accepted Answer

A)  The star is moving toward us. 
B)  The star is moving away from us. 
C)  The star is getting hotter. 
D)  The star is getting colder. 
E)  The "star" actually is a planet. 
A)  The star is moving toward us. 
B)  The star is moving away from us. 
C)  The star is getting hotter. 
D)  The star is getting colder. 
E)  The "star" actually is a planet.

Question 7

The Size of Molecules: You have a small flask of oil. You pour this oil onto a clear, calm pool of water and watch the oil slick spread out slowly with time. Imagine that it is your belief that the oil is not a continuous substance but made of individual particles called "molecules". Assuming this hypothesis is true, can you make a testable prediction on how the oil slick will behave as it spreads? Will this prediction allow you to estimate the size of the "molecules?" Search online to see if there is any evidence that the Greeks attempted such an experiment.

Accepted Answer

The answer of The Size of Molecules: You have a...

Question 8

Blue light hitting a red sweatshirt is an example of

Accepted Answer

A)  absorption. 
B)  reflection or scattering. 
C)  transmission. 
D)  emission. 
A)  absorption. 
B)  reflection or scattering. 
C)  transmission. 
D)  emission.

Question 9

Explain what an interferometer is and give an example.

Accepted Answer

Interferometers are groups of telescopes

Question 10

Suppose you see two stars: a blue star and a red star. Which of the following can you conclude about the two stars? Assume that no Doppler shifts are involved. (Hint: Think about the laws of thermal radiation.)

Accepted Answer

A)  The red star is more massive than the blue star. 
B)  The blue star is more massive than the red star. 
C)  The blue star is farther away than the red star. 
D)  The blue star has a hotter surface temperature than the red star. 
E)  The red star has a hotter surface temperature than the blue star. 
A)  The red star is more massive than the blue star. 
B)  The blue star is more massive than the red star. 
C)  The blue star is farther away than the red star. 
D)  The blue star has a hotter surface temperature than the red star. 
E)  The red star has a hotter surface temperature than the blue star.

Question 11

The frequency of a wave is

Accepted Answer

A)  the number of peaks passing by any point each second. 
B)  measured in cycles per second. 
C)  measured in hertz (Hz). 
D)  equal to the speed of the wave divided by the wavelength of the wave. 
E)  all of the above 
A)  the number of peaks passing by any point each second. 
B)  measured in cycles per second. 
C)  measured in hertz (Hz). 
D)  equal to the speed of the wave divided by the wavelength of the wave. 
E)  all of the above

Question 12

The energy levels for electrons vary from one element to another.

Accepted Answer

A) True 
 B)False

Question 13

Which of the following statements about X-rays and radio waves is not true?

Accepted Answer

A)  X-rays travel through space faster than radio waves. 
B)  X-rays have shorter wavelengths than radio waves. 
C)  X-rays and radio waves are both forms of light, or electromagnetic radiation. 
D)  X-rays have higher frequency than radio waves. 
A)  X-rays travel through space faster than radio waves. 
B)  X-rays have shorter wavelengths than radio waves. 
C)  X-rays and radio waves are both forms of light, or electromagnetic radiation. 
D)  X-rays have higher frequency than radio waves.

Question 14

Which of the following is an example of reﬂection or scattering?

Accepted Answer

A)  Red light hits a red sweatshirt. 
B)  Visible light does not pass through a black wall. 
C)  Blue light hits a red sweatshirt. 
D)  Light comes from your computer screen. 
A)  Red light hits a red sweatshirt. 
B)  Visible light does not pass through a black wall. 
C)  Blue light hits a red sweatshirt. 
D)  Light comes from your computer screen.

Question 15

If you heat a gas so that collisions are continually bumping electrons to higher energy levels, when the electrons fall back to lower energy levels the gas produces

Accepted Answer

A)  thermal radiation. 
B)  an absorption line spectrum. 
C)  an emission line spectrum. 
D)  X-rays. 
E)  radio waves. 
A)  thermal radiation. 
B)  an absorption line spectrum. 
C)  an emission line spectrum. 
D)  X-rays. 
E)  radio waves.

Question 16

Which of the following observational techniques is most appropriate for measuring Doppler shifts?

Accepted Answer

A)  Spectroscopy (taking a spectrum) 
B)  Imaging (taking a picture) 
C)  Timing (measuring how the amount of light changes with time) 
A)  Spectroscopy (taking a spectrum) 
B)  Imaging (taking a picture) 
C)  Timing (measuring how the amount of light changes with time)

Question 17

What is the angular resolution of the human eye?

Accepted Answer

A)  About 1 arcminute, or 1/60 of a degree 
B)  About 1 degree 
C)  About 1 arcsecond (1/3600 of a degree) 
D)  About 1 milliarcsecond 
A)  About 1 arcminute, or 1/60 of a degree 
B)  About 1 degree 
C)  About 1 arcsecond (1/3600 of a degree) 
D)  About 1 milliarcsecond

Question 18

Thermal radiation is defined as ________.

Accepted Answer

A)  radiation with a spectrum whose shape depends only on the temperature of the emitting object 
B)  radiation produced by an extremely hot object 
C)  radiation that is felt as heatradiation in the form of emission lines from an object 
A)  radiation with a spectrum whose shape depends only on the temperature of the emitting object 
B)  radiation produced by an extremely hot object 
C)  radiation that is felt as heatradiation in the form of emission lines from an object

Question 19

Explain why an absorption line spectrum is not filled back in (to make the original continuous spectrum) by the photons that are emitted as the excited electrons decay back down to their original energy levels.

Accepted Answer

The photons emitted by the dec

Question 20

If a material is transparent, then it

Accepted Answer

A)  reflects light well. 
B)  absorbs light well. 
C)  transmits light well. 
D)  scatters light well. 
E)  emits light well. 
A)  reflects light well. 
B)  absorbs light well. 
C)  transmits light well. 
D)  scatters light well. 
E)  emits light well.

The energy levels of an element and its ion are the same.

The diagram represents energy levels in a hydrogen atom. The labeled transitions (A through E. represent an electron moving between energy levels. Suppose that an electron in a hydrogen atom absorbs 10.2 eV of energy, so that it moves from level 1 to level 2. What typically happens next?

If a hydrogen emission line appears at 656.2 nm in the laboratory, what can we say about a cloud of hydrogen gas, with an emission line at 680.2 nm?

Which of the following would be the most capable ultraviolet telescope?

From laboratory measurements, we know that a particular spectral line formed by hydrogen appears at a wavelength of 121.6 nanometers (nm). The spectrum of a particular star shows the same hydrogen line appearing at a wavelength of 121.8 nm. What can we conclude?

Blue light hitting a red sweatshirt is an example of

Explain what an interferometer is and give an example.

Suppose you see two stars: a blue star and a red star. Which of the following can you conclude about the two stars? Assume that no Doppler shifts are involved. (Hint: Think about the laws of thermal radiation.)

The frequency of a wave is

The energy levels for electrons vary from one element to another.

Which of the following statements about X-rays and radio waves is not true?

Which of the following is an example of reﬂection or scattering?

If you heat a gas so that collisions are continually bumping electrons to higher energy levels, when the electrons fall back to lower energy levels the gas produces

Which of the following observational techniques is most appropriate for measuring Doppler shifts?

What is the angular resolution of the human eye?

Thermal radiation is defined as ________.

Explain why an absorption line spectrum is not filled back in (to make the original continuous spectrum) by the photons that are emitted as the excited electrons decay back down to their original energy levels.

If a material is transparent, then it

Our Place in the Universe

Discovering the Universe for Yourself

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Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Formation of Planetary Systems: Our Solar System and Beyond

Earth and the Terrestrial Worlds

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Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Our Star

Surveying the Stars

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Exam 5: Light: the Cosmic Messenger

The energy levels of an element and its ion are the same.

The diagram represents energy levels in a hydrogen atom. The labeled transitions (A through E. represent an electron moving between energy levels. Suppose that an electron in a hydrogen atom absorbs 10.2 eV of energy, so that it moves from level 1 to level 2. What typically happens next?

If a hydrogen emission line appears at 656.2 nm in the laboratory, what can we say about a cloud of hydrogen gas, with an emission line at 680.2 nm?

Which of the following would be the most capable ultraviolet telescope?

From laboratory measurements, we know that a particular spectral line formed by hydrogen appears at a wavelength of 121.6 nanometers (nm). The spectrum of a particular star shows the same hydrogen line appearing at a wavelength of 121.8 nm. What can we conclude?

Blue light hitting a red sweatshirt is an example of

Explain what an interferometer is and give an example.

Suppose you see two stars: a blue star and a red star. Which of the following can you conclude about the two stars? Assume that no Doppler shifts are involved. (Hint: Think about the laws of thermal radiation.)

The frequency of a wave is

The energy levels for electrons vary from one element to another.

Which of the following statements about X-rays and radio waves is not true?

Which of the following is an example of reﬂection or scattering?

If you heat a gas so that collisions are continually bumping electrons to higher energy levels, when the electrons fall back to lower energy levels the gas produces

Which of the following observational techniques is most appropriate for measuring Doppler shifts?

What is the angular resolution of the human eye?

Thermal radiation is defined as ________.

Explain why an absorption line spectrum is not filled back in (to make the original continuous spectrum) by the photons that are emitted as the excited electrons decay back down to their original energy levels.

If a material is transparent, then it

Our Place in the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Formation of Planetary Systems: Our Solar System and Beyond

Earth and the Terrestrial Worlds

Jovian Planet Systems

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Our Star

Surveying the Stars

Star Stuff

Bizarre Stellar Graveyard

Our Galaxy

Galaxies and the Foundation of Modern Cosmology

Dark Matter, Dark Energy, and the Fate of the Universe

The Beginning of Time

Life in the Universe

Filters