Question 1

What value of n corresponds to a wavelength of 922.7 nm in the Paschen series?

Accepted Answer

A)  3 
B)  5 
C)  15 
D)  9 
E)  7 
A)  3 
B)  5 
C)  15 
D)  9 
E)  7

Question 2

If the wavelength of a photon is the same as the de Broglie wavelength of an electron, which one has the greater momentum?

Accepted Answer

A)  The photon because it is traveling faster. 
B)  The electron because it has more mass. 
C)  They both have the same momentum. 
A)  The photon because it is traveling faster. 
B)  The electron because it has more mass. 
C)  They both have the same momentum.

Question 3

What is the energy (in electron-volts) of the n = 3 state of atomic hydrogen?

Accepted Answer

The answer of What is the energy (in electron-volts) of...

Question 4

How "slow" must a 200-g ball move to have a de Broglie wavelength of $1.0 \mathrm {~mm}$ ? $( h =$
$$6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } \text { ) }$$

Accepted Answer

The answer of How "slow" must a 200-g ball move...

Question 5

A beam of light with a frequency range from $3.01 \times 10 ^ { 14 } \mathrm {~Hz}$ to $6.10 \times 10 ^ { 14 } \mathrm {~Hz}$ is incident on a metal surface. If the work function of the metal surface is $2.20 \mathrm { eV }$, what is the maximum kinetic energy of photoelectrons ejected from this surface? $\left( h = 6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } , 1 \mathrm { eV } = 1.60 \times 10 ^ { - 19 } \mathrm {~J} \right)$

Accepted Answer

A)  $0.33 \mathrm { eV }$ 
B)  $0.16 \mathrm { eV }$ 
C)  $0.48 \mathrm { eV }$ 
D)  $0.21 \mathrm { eV }$ 
E)  $0.42 \mathrm { eV }$ 
A)  $0.33 \mathrm { eV }$ 
B)  $0.16 \mathrm { eV }$ 
C)  $0.48 \mathrm { eV }$ 
D)  $0.21 \mathrm { eV }$ 
E)  $0.42 \mathrm { eV }$

Question 6

In the $n = 1$ state, the energy of the hydrogen atom is $- 13.6 \mathrm { eV }$. What is its energy in the $n = 2$ state?

Accepted Answer

A)  $- 6.79 \mathrm { eV }$ 
B)  $- 4.53 \mathrm { eV }$ 
C)  $- 1.51 \mathrm { eV }$ 
D)  $- 3.40 \mathrm { eV }$ 
A)  $- 6.79 \mathrm { eV }$ 
B)  $- 4.53 \mathrm { eV }$ 
C)  $- 1.51 \mathrm { eV }$ 
D)  $- 3.40 \mathrm { eV }$

Question 7

If a proton and an electron have the same de Broglie wavelengths, which one is moving faster?

Accepted Answer

A)  the proton 
B)  the electron 
C)  They both have the same speed. 
A)  the proton 
B)  the electron 
C)  They both have the same speed.

Question 8

When it is struck by $240 - \mathrm { nm }$ photons, a metal ejects electrons with a maximum kinetic energy of $2.58 \mathrm { eV }$. What is the work function of this material? $\left( c = 3.00 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } , h = 6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } , 1 \mathrm { eV } \right.$ $= 16.0 \times 10 ^ { - 19 } \mathrm {~J}$ )

Accepted Answer

A)  $3.02 \mathrm { eV }$ 
B)  $2.60 \mathrm { eV }$ 
C)  $3.43 \mathrm { eV }$ 
D)  $2.18 \mathrm { eV }$ 
A)  $3.02 \mathrm { eV }$ 
B)  $2.60 \mathrm { eV }$ 
C)  $3.43 \mathrm { eV }$ 
D)  $2.18 \mathrm { eV }$

Question 9

Given that the energy levels of the hydrogen atom are given by $E _ { n } = \frac { R c h } { n ^ { 2 } }$, where $R = 1.097$ $\times 10 ^ { 7 } \mathrm {~m} ^ { - 1 }$, what wavelength photon is emitted when the atom undergoes a transition from the $n = 4$ to the $n = 6$ level?

Accepted Answer

The answer of Given that the energy levels of the...

Question 10

If the sunlight from a star peaks at a wavelength of $0.55 \mu \mathrm { m }$, what temperature does this imply for the surface of that star? The constant in Wien's law is $0.00290 \mathrm {~m} \cdot \mathrm { K }$.

Accepted Answer

A)  $9500 \mathrm {~K}$ 
B)  $25,000 \mathrm {~K}$ 
C)  $5300 \mathrm {~K}$ 
D)  $15,000 \mathrm {~K}$ 
E)  $2500 \mathrm {~K}$ 
A)  $9500 \mathrm {~K}$ 
B)  $25,000 \mathrm {~K}$ 
C)  $5300 \mathrm {~K}$ 
D)  $15,000 \mathrm {~K}$ 
E)  $2500 \mathrm {~K}$

Question 11

When light of wavelength $350 \mathrm {~nm}$ is incident on a metal surface, the stopping potential of the photoelectrons is $0.500 \mathrm {~V}$. What is the maximum kinetic energy of these electrons? $\left( c = 3.00 \times 10 ^ { 8 } \right.$ $\mathrm { m } / \mathrm { s } , h = 6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } , 1 \mathrm { eV } = 1.60 \times 10 ^ { - 19 } \mathrm {~J}$ )

Accepted Answer

A)  $3.04 \mathrm { eV }$ 
B)  $3.54 \mathrm { eV }$ 
C)  $0.500 \mathrm { eV }$ 
D)  $4.12 \mathrm { eV }$ 
A)  $3.04 \mathrm { eV }$ 
B)  $3.54 \mathrm { eV }$ 
C)  $0.500 \mathrm { eV }$ 
D)  $4.12 \mathrm { eV }$

Question 12

What is the momentum of a photon of light that has a frequency of $2.8 \times 10 ^ { 14 } \mathrm {~Hz}$ ? $\left( c = 3.00 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } , h = 6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } \right)$

Accepted Answer

A)  $1.5 \times 10 ^ { - 28 } \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$ 
B)  $6.2 \times 10 ^ { - 28 } \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$ 
C)  $4.4 \times 10 ^ { - 28 } \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$ 
D)  $6.3 \times 10 ^ { - 28 } \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$ 
E)  $2.1 \times 10 ^{- 28} \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$ 
A)  $1.5 \times 10 ^ { - 28 } \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$ 
B)  $6.2 \times 10 ^ { - 28 } \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$ 
C)  $4.4 \times 10 ^ { - 28 } \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$ 
D)  $6.3 \times 10 ^ { - 28 } \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$ 
E)  $2.1 \times 10 ^{- 28} \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$

Question 13

Gamma rays are photons with very high energy. What is the wavelength of a gamma-ray photon with energy $7.7 \times 10 ^ { - 13 } \mathrm {~J}$ ? $\left( c = 3.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } , h = 6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } \right)$

Accepted Answer

A)  $2.6 \times 10 ^ { - 13 } \mathrm {~m}$ 
B)  $3.5 \times 10 ^ { - 13 } \mathrm {~m}$ 
C)  $3.9 \times 10 ^ { - 13 } \mathrm {~m}$ 
D)  $3.1 \times 10 ^ { - 13 } \mathrm {~m}$ 
A)  $2.6 \times 10 ^ { - 13 } \mathrm {~m}$ 
B)  $3.5 \times 10 ^ { - 13 } \mathrm {~m}$ 
C)  $3.9 \times 10 ^ { - 13 } \mathrm {~m}$ 
D)  $3.1 \times 10 ^ { - 13 } \mathrm {~m}$

Question 14

The work function of a particular metal is $4.20 \times 10 ^ { - 19 } \mathrm {~J}$. What is the photoelectric cutoff (threshold) wavelength for this metal? $\left( c = 3.00 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } , h = 6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } \right)$

Accepted Answer

A)  $308 \mathrm {~nm}$ 
B)  $554 \mathrm {~nm}$ 
C)  $393 \mathrm {~nm}$ 
D)  $473 \mathrm {~nm}$ 
A)  $308 \mathrm {~nm}$ 
B)  $554 \mathrm {~nm}$ 
C)  $393 \mathrm {~nm}$ 
D)  $473 \mathrm {~nm}$

Question 15

One of the emission lines described by the original version of Balmer's formula has wavelength 377 nm. What is the value of n in Balmer's formula that gives this emission line?

Accepted Answer

A)  12 
B)  11 
C)  13 
D)  14 
A)  12 
B)  11 
C)  13 
D)  14

Question 16

X-rays with a wavelength of $0.00100 \mathrm {~nm}$ are scattered by free electrons at $130 ^ { \circ }$ from their original direction. What is the kinetic energy (in $\mathrm { keV } )$ of each recoil electron? ( $m _ { \text {electron } } =$ $\left. 9.11 \times 10 ^ { - 31 } \mathrm {~kg} , c = 3.00 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } , 1 \mathrm { eV } = 1.60 \times 10 ^ { - 19 } \mathrm {~J} , h = 6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } \right)$

Accepted Answer

The answer of X-rays with a wavelength of \(0.00100 \mathrm...

Question 17

A photon of blue light and a photon of red light are traveling in vacuum. The photon of blue light

Accepted Answer

A)  has a longer wavelength than a photon of red light and travels with the same speed. 
B)  has a longer wavelength than a photon of red light and travels with a greater speed. 
C)  has a smaller wavelength than a photon of red light and travels with the same speed. 
D)  has a smaller wavelength than a photon of red light and travels with a greater speed. 
A)  has a longer wavelength than a photon of red light and travels with the same speed. 
B)  has a longer wavelength than a photon of red light and travels with a greater speed. 
C)  has a smaller wavelength than a photon of red light and travels with the same speed. 
D)  has a smaller wavelength than a photon of red light and travels with a greater speed.

Question 18

A photoelectric surface has a work function of $2.10 \mathrm { eV }$. Calculate the maximum kinetic energy, in $\mathrm { eV }$, of electrons ejected from this surface by electromagnetic radiation of wavelength $356 \mathrm {~nm} . \left( 1 \mathrm { eV } = 1.60 \times 10 ^ { - 19 } \mathrm {~J} , c = 3.00 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } , h = 6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } \right)$

Accepted Answer

The answer of A photoelectric surface has a work function...

Question 19

A beam of light falling on a metal surface is causing electrons to be ejected from the surface. If we now double the frequency of the light, which of the following statements are correct? (There could
Be more than one correct choice.)

Accepted Answer

A)  The number of electrons ejected per second doubles. 
B)  The speed of the ejected electrons doubles. 
C)  Twice as many photons hit the metal surface as before. 
D)  The kinetic energy of the ejected electrons doubles. 
E)  None of the above things occur. 
A)  The number of electrons ejected per second doubles. 
B)  The speed of the ejected electrons doubles. 
C)  Twice as many photons hit the metal surface as before. 
D)  The kinetic energy of the ejected electrons doubles. 
E)  None of the above things occur.

Question 20

Calculate the kinetic energy, in electron-volts, of a neutron that has a de Broglie wavelength of $7.2 \times 10 ^ { - 12 } \mathrm {~m}$ ( $m _ { \text {neutron } } = 1.675 \times 10 ^ { - 27 } \mathrm {~kg} , 1 \mathrm { eV } = 1.6 \times 10 ^ { - 19 } \mathrm {~J} , h = 6.626$ $\times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s }$ )

Accepted Answer

The answer of Calculate the kinetic energy, in electron-volts, of...

Exam 27: Early Quantum Theory and Models of the Atom

What value of n corresponds to a wavelength of 922.7 nm in the Paschen series?

If the wavelength of a photon is the same as the de Broglie wavelength of an electron, which one has the greater momentum?

What is the energy (in electron-volts) of the n = 3 state of atomic hydrogen?

How "slow" must a 200-g ball move to have a de Broglie wavelength of 1.0 mm1.0 \mathrm {~mm}1.0 mm ? (h=( h =(h= 6.626×10−34 J⋅s ) 6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } \text { ) }6.626×10−34 J⋅s )

In the n=1n = 1n=1 state, the energy of the hydrogen atom is −13.6eV- 13.6 \mathrm { eV }−13.6eV . What is its energy in the n=2n = 2n=2 state?

If a proton and an electron have the same de Broglie wavelengths, which one is moving faster?

If the sunlight from a star peaks at a wavelength of 0.55μm0.55 \mu \mathrm { m }0.55μm , what temperature does this imply for the surface of that star? The constant in Wien's law is 0.00290 m⋅K0.00290 \mathrm {~m} \cdot \mathrm { K }0.00290 m⋅K .

One of the emission lines described by the original version of Balmer's formula has wavelength 377 nm. What is the value of n in Balmer's formula that gives this emission line?

A photon of blue light and a photon of red light are traveling in vacuum. The photon of blue light

A beam of light falling on a metal surface is causing electrons to be ejected from the surface. If we now double the frequency of the light, which of the following statements are correct? (There could Be more than one correct choice.)

Introduction, Measurement, Estimating

Describing Motion: Kinematics in One Dimension

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Dynamics: Newtons Laws of Motion

Circular Motion; Gravitation

Work and Energy

Linear Momentum

Rotational Motion

Static Equilibrium; Elasticity and Fracture

Fluids

Oscillations and Waves

Sound

Temperature and Kinetic Theory

Heat

The Laws of Thermodynamics

Electric Charge and Electric Field

Electric Potential

Electric Currents

Dc Circuits

Magnetism

Electromagnetic Induction and Faradays Law

Electromagnetic Waves

Light: Geometric Optics

The Wave Nature of Light

Optical Instruments

The Special Theory of Relativity

Quantum Mechanics of Atoms

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Nuclear Energy; Effects and Uses of Radiation

Elementary Particles

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How "slow" must a 200-g ball move to have a de Broglie wavelength of $1.0 \mathrm {~mm}$ ? $( h =$ $6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } \text { ) }$

In the $n = 1$ state, the energy of the hydrogen atom is $- 13.6 \mathrm { eV }$ . What is its energy in the $n = 2$ state?

If the sunlight from a star peaks at a wavelength of $0.55 \mu \mathrm { m }$ , what temperature does this imply for the surface of that star? The constant in Wien's law is $0.00290 \mathrm {~m} \cdot \mathrm { K }$ .