Question 1

Astronomers can tell whether a star is approaching or receding from Earth by

Accepted Answer

A)  its temperature.
B)  its change in temperature.
C)  its absorption spectra.
D)  the Doppler effect.
E)  all of these

Question 2

The hottest star is the star that glows

Accepted Answer

A)  red.
B)  white.
C)  blue.
D)  cannot be determined by color alone C

Question 3

Spectral lines take the shape of vertical lines because

Accepted Answer

A)  the light is vertically polarized.
B)  they are simply images of a vertical slit.
C)  the energy levels in the atom are parallel to one another.
D)  all of these
E)  none of these

Question 4

Ultraviolet light is

Accepted Answer

A)  more energetic than X-rays.
B)  produced by crossed Polaroids.
C)  electromagnetic energy.
D)  present everywhere.
E)  none of these

Question 5

Sometimes a flashlight filament glows red instead of white.This indicates a lowness of

Accepted Answer

A)  current in the filament.
B)  battery strength.
C)  filament temperature.
D)  all of these
E)  none of these

Question 6

A paint pigment that absorbs red light and gives off blue light

Accepted Answer

A)  is fluorescent.
B)  is phosphorescent.
C)  is used in lasers.
D)  is polarized.
E)  doesn't exist.

Question 7

A throbbing pulse of electromagnetic radiation is called a

Accepted Answer

A)  proton.
B)  photon.
C)  lightron.
D)  sparktron.
E)  notron.

Question 8

An excited atom is an atom

Accepted Answer

A)  that has excess vibration.
B)  that has one or more displaced electrons.
C)  with more protons than electrons.
D)  that is frantic.

Question 9

Helium was first discovered in the

Accepted Answer

A)  laboratory.
B)  upper atmosphere.
C)  sun.
D)  island of Helios,in Greece.
E)  by-products of nuclear fusion.

Question 10

Compared to the energy of a photon of red light,the energy of a photon of blue light is

Accepted Answer

A)  less.
B)  more.
C)  the same.

Question 11

Which of the following continually emits electromagnetic radiation?

Accepted Answer

A)  insects
B)  radio antennas
C)  red-hot coals
D)  all of these
E)  none of these

Question 12

If the energy levels in the neon atom were not discrete,neon signs would glow

Accepted Answer

A)  red.
B)  white.
C)  blue. B

Question 13

Atoms of neon in a glass tube can be excited

Accepted Answer

A)  once per atom.
B)  over and over again.

Question 14

The radiation curve for a "blue hot" object peaks in the

Accepted Answer

A)  infrared region.
B)  red region.
C)  yellow region.
D)  ultraviolet region.
E)  none of these

Question 15

Which light source is more energy-efficient?

Accepted Answer

A)  a fluorescent lamp
B)  an incandescent lamp
C)  both about the same

Question 16

The Doppler effect from the back-and-forth motion of atoms in a glowing discharge tube tends to make the spectral lines slightly

Accepted Answer

A)  thicker.
B)  thinner.
C)  more numerous.
D)  none of these

Question 17

An atom that emits a certain frequency of light is

Accepted Answer

A)  not likely to absorb that same frequency.
B)  an absorber of the same frequency.

Question 18

Discrete spectral lines occur when excitation takes place in a

Accepted Answer

A)  solid.
B)  liquid.
C)  gas.
D)  superconductor.
E)  all of these

Question 19

Electrons with the greater potential energies with respect to the atomic nucleus are

Accepted Answer

A)  inner electrons.
B)  outer electrons.
C)  both the same,actually B

Question 20

The highest frequency light of those below is

Accepted Answer

A)  red.
B)  green.
C)  blue.
D)  violet.
E)  all the same

Exam 30: Light Emission

Astronomers can tell whether a star is approaching or receding from Earth by

Correct AnswerverifiedShow Answer

The hottest star is the star that glows

Correct AnswerverifiedC

Spectral lines take the shape of vertical lines because

Correct AnswerverifiedShow Answer

Ultraviolet light is

Correct AnswerverifiedShow Answer

Sometimes a flashlight filament glows red instead of white.This indicates a lowness of

Correct AnswerverifiedShow Answer

A paint pigment that absorbs red light and gives off blue light

Correct AnswerverifiedShow Answer

A throbbing pulse of electromagnetic radiation is called a

Correct AnswerverifiedShow Answer

An excited atom is an atom

Correct AnswerverifiedShow Answer

Helium was first discovered in the

Correct AnswerverifiedShow Answer

Compared to the energy of a photon of red light,the energy of a photon of blue light is

Correct AnswerverifiedShow Answer

Which of the following continually emits electromagnetic radiation?

Correct AnswerverifiedShow Answer

If the energy levels in the neon atom were not discrete,neon signs would glow

Correct AnswerverifiedB

Atoms of neon in a glass tube can be excited

Correct AnswerverifiedShow Answer

The radiation curve for a "blue hot" object peaks in the

Correct AnswerverifiedShow Answer

Which light source is more energy-efficient?

Correct AnswerverifiedShow Answer

The Doppler effect from the back-and-forth motion of atoms in a glowing discharge tube tends to make the spectral lines slightly

Correct AnswerverifiedShow Answer

An atom that emits a certain frequency of light is

Correct AnswerverifiedShow Answer

Discrete spectral lines occur when excitation takes place in a

Correct AnswerverifiedShow Answer

Electrons with the greater potential energies with respect to the atomic nucleus are

Correct AnswerverifiedB

The highest frequency light of those below is

Correct AnswerverifiedShow Answer

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C

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B

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B

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