Question 1

How much would you have to change the temperature of an object if you wanted to increase its flux by a factor of 100?

Accepted Answer

Because flux is proportional to T⁴,you would have to raise the object's temperature by a factor of 100^1/4 = 3.16.

Question 2

Why is a neutral iron atom a different element from a neutral carbon atom?

Accepted Answer

A)  A carbon atom has fewer neutrons in its nucleus than an iron atom. 
B)  An iron atom has more protons in its nucleus than a carbon atom. 
C)  An iron atom has more electrons than a carbon atom. 
D)  A carbon atom is bigger than an iron atom. 
E)  None of these is correct. 
A)  A carbon atom has fewer neutrons in its nucleus than an iron atom. 
B)  An iron atom has more protons in its nucleus than a carbon atom. 
C)  An iron atom has more electrons than a carbon atom. 
D)  A carbon atom is bigger than an iron atom. 
E)  None of these is correct. B

Question 3

You observe the spectrum of two stars.Star A has an emission line from a known element at 600 nm.Star B has emission lines from the same atom, but the emission line is occurring at 650 nm.One possible explanation for this observation is that star A is

Accepted Answer

A)  cooler than star B. 
B)  farther away from us than star B. 
C)  moving toward us faster than star B. 
D)  made of different elements than star B. 
E)  larger than star B. 
A)  cooler than star B. 
B)  farther away from us than star B. 
C)  moving toward us faster than star B. 
D)  made of different elements than star B. 
E)  larger than star B. C

Question 4

If you were driving down a deserted country road and you saw a light in the distance, what would you need to measure or know about it in order to calculate how far away it was?

Accepted Answer

You would need to kn

Question 5

A certain light wave has a frequency of 3 *108 Hz.What is its wavelength?

Accepted Answer

A)  500 nanometers 
B)  10 nanometers 
C)  100 microns 
D)  1.0 meter 
E)  3 * 108 meters 
A)  500 nanometers 
B)  10 nanometers 
C)  100 microns 
D)  1.0 meter 
E)  3 * 108 meters

Question 6

As wavelength increases, the energy of a photon ________ and its frequency ________.

Accepted Answer

A)  increases; decreases 
B)  increases; increases 
C)  decreases; decreases 
D)  decreases; increases 
E)  decreases; does not change. 
A)  increases; decreases 
B)  increases; increases 
C)  decreases; decreases 
D)  decreases; increases 
E)  decreases; does not change.

Question 7

If the frequency of a beam of light were to increase, its period would ________ and its wavelength would ________.

Accepted Answer

A)  decrease; increase 
B)  increase; decrease 
C)  increase; increase 
D)  decrease; decrease 
E)  stay the same; stay the same 
A)  decrease; increase 
B)  increase; decrease 
C)  increase; increase 
D)  decrease; decrease 
E)  stay the same; stay the same

Question 8

Astronomers have now found a large number of exoplanets, which are planets that orbit around stars other than the Sun.Imagine astronomers found a planet identical to Earth orbiting a star that had the same radius as the Sun, but with a temperature that is twice the temperature of the Sun.How far would this new planet need to be away from its star to have the same average temperature as Earth?

Accepted Answer

In order to have the same average temper

Question 9

A red photon has a wavelength of 650 nm.An ultraviolet photon has a wavelength of 250 nm.The energy of an ultraviolet photon is ________ the energy of a red photon.

Accepted Answer

A)  2.6 times larger than 
B)  6.8 times larger than 
C)  2.6 times smaller than 
D)  6.8 times smaller than 
E)  the same as 
A)  2.6 times larger than 
B)  6.8 times larger than 
C)  2.6 times smaller than 
D)  6.8 times smaller than 
E)  the same as

Question 10

In the energy level diagram shown in the figure below, the electron is excited to the E2 energy level.If the atom absorbs a photon with the exact wavelength to move the electron to another energy level, which energy level would correspond to the incoming photon with the largest wavelength?

Accepted Answer

A)  E1 
B)  E2 
C)  E3 
D)  E4 
E)  E5 
A)  E1 
B)  E2 
C)  E3 
D)  E4 
E)  E5

Question 11

The difference in energy between the n = 2 and n =1 electronic energy levels in the hydrogen atom is 1.6 *10-18 J.If an electron moves from the n = 1 level to the n=2 level, will a photon be emitted or absorbed? What will its energy be, and what type of electromagnetic radiation is it? Use the electromagnetic spectrum shown in the figure below to answer this question.

Accepted Answer

The n =2 energy level is higher than the

Question 12

Why do we see black lines in an absorption spectrum if the absorbed photons are (almost) instantaneously reemitted by the atoms in the cloud?

Accepted Answer

Originally all the light was traveling i

Question 13

Which of these planets would be expected to have the highest average temperature?

Accepted Answer

A)  a light-colored planet close to its star 
B)  a dark-colored planet close to its star 
C)  a light-colored planet far from its star 
D)  a dark-colored planet far from its star 
E)  There is not enough information to know which would be the hottest. 
A)  a light-colored planet close to its star 
B)  a dark-colored planet close to its star 
C)  a light-colored planet far from its star 
D)  a dark-colored planet far from its star 
E)  There is not enough information to know which would be the hottest.

Question 14

If you are standing in a fixed location, you may notice that the pitch of a passing train's whistle changes.What produces this effect?

Accepted Answer

Because sound is a wave,it can also expe

Question 15

In the energy level diagram shown in the figure below, the electron is excited to the E4 energy level.If the electron transitions to an energy level giving off a photon, which level would produce a photon with the largest frequency?

Accepted Answer

A)  E1 
B)  E2 
C)  E3 
D)  E4 
E)  E5 
A)  E1 
B)  E2 
C)  E3 
D)  E4 
E)  E5

Question 16

Describe, in your own words, why electrons cannot orbit the nucleus like the planets orbit the Sun.

Accepted Answer

In this model,the electron is constantly

Question 17

How does temperature relate to the speed of gas particles?

Accepted Answer

Higher-temperature g

Question 18

The n = 5 electronic energy level in a hydrogen atom is 1.5 *10-19 J higher than the n = 3 level.If an electron moves from the n = 5 level to the n = 3 level, then a photon of wavelength

Accepted Answer

A)  1.3 nm, which is in the ultraviolet region, is emitted. 
B)  1.3 nm, which is in the ultraviolet region, is absorbed. 
C)  1,300 nm, which is in the infrared region, is absorbed. 
D)  1,300 nm, which is in the infrared region, is emitted. 
E)  No light will be absorbed or emitted. 
A)  1.3 nm, which is in the ultraviolet region, is emitted. 
B)  1.3 nm, which is in the ultraviolet region, is absorbed. 
C)  1,300 nm, which is in the infrared region, is absorbed. 
D)  1,300 nm, which is in the infrared region, is emitted. 
E)  No light will be absorbed or emitted.

Question 19

Which of these objects would emit an absorption spectrum?

Accepted Answer

A)  an incandescent lightbulb 
B)  a fluorescent lightbulb 
C)  an isolated hot gas cloud 
D)  a hot, solid object 
E)  a thin, cool gas cloud that lies in front of a hotter blackbody 
A)  an incandescent lightbulb 
B)  a fluorescent lightbulb 
C)  an isolated hot gas cloud 
D)  a hot, solid object 
E)  a thin, cool gas cloud that lies in front of a hotter blackbody

Question 20

Which formula denotes how the speed of light is related to its wavelength and frequency?

Accepted Answer

A)  c = $\lambda$f 
B)  c = $\lambda$/f 
C)  c =f / $\lambda$ 
D)  c = 1/$\lambda$f 
E)  There is no relationship between wavelength and frequency. 
A)  c = $\lambda$f 
B)  c = $\lambda$/f 
C)  c =f / $\lambda$ 
D)  c = 1/$\lambda$f 
E)  There is no relationship between wavelength and frequency.

Exam 5: Light

How much would you have to change the temperature of an object if you wanted to increase its flux by a factor of 100?

Why is a neutral iron atom a different element from a neutral carbon atom?

You observe the spectrum of two stars.Star A has an emission line from a known element at 600 nm.Star B has emission lines from the same atom, but the emission line is occurring at 650 nm.One possible explanation for this observation is that star A is

If you were driving down a deserted country road and you saw a light in the distance, what would you need to measure or know about it in order to calculate how far away it was?

A certain light wave has a frequency of 3 *108 Hz.What is its wavelength?

As wavelength increases, the energy of a photon ________ and its frequency ________.

If the frequency of a beam of light were to increase, its period would ________ and its wavelength would ________.

A red photon has a wavelength of 650 nm.An ultraviolet photon has a wavelength of 250 nm.The energy of an ultraviolet photon is ________ the energy of a red photon.

In the energy level diagram shown in the figure below, the electron is excited to the E2 energy level.If the atom absorbs a photon with the exact wavelength to move the electron to another energy level, which energy level would correspond to the incoming photon with the largest wavelength?

Why do we see black lines in an absorption spectrum if the absorbed photons are (almost) instantaneously reemitted by the atoms in the cloud?

Which of these planets would be expected to have the highest average temperature?

If you are standing in a fixed location, you may notice that the pitch of a passing train's whistle changes.What produces this effect?

In the energy level diagram shown in the figure below, the electron is excited to the E4 energy level.If the electron transitions to an energy level giving off a photon, which level would produce a photon with the largest frequency?

Describe, in your own words, why electrons cannot orbit the nucleus like the planets orbit the Sun.

How does temperature relate to the speed of gas particles?

The n = 5 electronic energy level in a hydrogen atom is 1.5 *10-19 J higher than the n = 3 level.If an electron moves from the n = 5 level to the n = 3 level, then a photon of wavelength

Which of these objects would emit an absorption spectrum?

Which formula denotes how the speed of light is related to its wavelength and frequency?

Thinking Like an Astronomer

Patterns in the Skymotions of Earth and the Moon

Motion of Astronomical Bodies

Gravity and Orbits

The Tools of the Astronomer

The Formation of Planetary Systems

The Terrestrial Planets and Earths Moon

Atmospheres of the Terrestrial Planets

Worlds of Gas and Liquidthe Giant Planets

Planetary Moons and Rings

Dwarf Planets and Small Solar System Bodies

Taking the Measure of Stars

Our Starthe Sun

The Interstellar Medium and Star Formation

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

Relativity and Black Holes

Galaxies

The Milky Waya Normal Spiral Galaxy

The Expanding Universe

Cosmology

Large-Scale Structure in the Universe

Life

Filters

A certain light wave has a frequency of 3 *10⁸ Hz.What is its wavelength?

As wavelength increases, the energy of a photon and its frequency .

If the frequency of a beam of light were to increase, its period would and its wavelength would .

In the energy level diagram shown in the figure below, the electron is excited to the E₂ energy level.If the atom absorbs a photon with the exact wavelength to move the electron to another energy level, which energy level would correspond to the incoming photon with the largest wavelength?

In the energy level diagram shown in the figure below, the electron is excited to the E₄ energy level.If the electron transitions to an energy level giving off a photon, which level would produce a photon with the largest frequency?

The n = 5 electronic energy level in a hydrogen atom is 1.5 *10^-¹⁹ J higher than the n = 3 level.If an electron moves from the n = 5 level to the n = 3 level, then a photon of wavelength