Deck 38: Atomic Physics

Question 1

The energy contained in a length of a 3.00-mW laser beam in vacuum is 1.80 * 10^-10 J.What is the length of the beam?

A)2.0 m
B)24 m
C)15 m
D)18 m

Answer 1

18 m

Question 2

How much energy is contained in a 3.00-mW laser beam of length 2.00 m that moves through vacuum?

A)2.00 * 10^-11 J
B)1.80 * 10^-10 J
C)2.00 * 10^-8 J
D)1.80 * 10^-7 J

Answer 2

2.00 * 10^-11 J

Question 3

The energy contained in laser beam of length 2.00 m that moves through vacuum is 1.80 * 10^-10 J.What is the power of the laser?

A)3.0 mW
B)12 mW
C)23 mW
D)27 mW

Answer 3

27 mW

Question 4

The wavelength of the line of the Lyman group for the hydrogen spectrum is

A)93 nm.
B)106 nm.
C)250 nm.
D)397 nm.

Question 5

The energy required to ionize hydrogen when the electron is in the second level is _______ the energy required to ionize hydrogen when electron is in the first level.

A)twice
B)half of
C)four times
D)one fourth of
E)equal to

Question 6

If the period of rotation of electron in the Bohr hydrogen atom is 4.10 fs,which Bohr orbit does the electron occupy?

A)first
B)second
C)third
D)fourth
E)fifth

Question 7

The period of rotation of electron on the 6-th Bohr orbit is __________ the period of rotation of electron on the 3- rd Bohr orbit.

A)equal to
B)twice
C)four times
D)six times
E)eight times

Question 8

The electron in a singly ionized helium atom,which consists of two protons,two neutrons and only one electron,makes a transition from the n = 2 state to the n = 1 state,emitting a single photon in the process.What is the energy of this photon?

A)3.40 eV
B)10.2 eV
C)13.6 eV
D)40.8 eV
E)None are correct.

Question 9

The wavelength of the line of the Balmer group for the hydrogen spectrum is

A)105 nm.
B)286 nm.
C)371 nm.
D)434 nm.

Question 10

A photon needed to excite an electron from the to the state.What is the energy of the photon?

A)2.55 eV
B)6.61 eV
C)9.25 eV
D)12.8 eV
E)20.4 eV

Question 11

The frequency of the line of the Lyman group for the hydrogen spectrum is

A)9.88 * 10¹⁴ Hz
B)3.22 * 10¹⁵ Hz
C)1.21 * 10¹⁵ Hz
D)2.25 * 10¹⁵ Hz

Question 12

Positronium consists of a bound state of an electron and a positron.A positron is exactly the same as an electron,except it has a charge of +e instead of -e.In the classical model,both particles orbit a point midway between them.The reduced mass of positronium is equal to

A)the mass of an electron.
B)the mass of an electron squared.
C)the square root of the mass of an electron.
D)None are correct.

Question 13

The Bohr model of hydrogen is based on the quantization of

A)electrical charge.
B)orbital angular momentum.
C)electric force.
D)magnetic force.

Question 14

The minimum orbital angular momentum quantum number for the is

A)0.
B)1.
C)2.
D)3.
E)4.

Question 15

The frequency of the line of the Balmer group for the hydrogen spectrum is

A)6.91 * 10¹⁴ Hz
B)7.33 * 10¹⁴ Hz
C)9.05 * 10¹⁴ Hz
D)8.54 * 10¹⁴ Hz

Question 16

The electron in a singly ionized helium atom,which consists of two protons,two neutrons and only one electron,makes a transition from the n = 2 state to the n = 1 state,emitting a single photon in the process.What is the energy of this photon?

A)3.40 eV
B)10.2 eV
C)13.6 eV
D)None are correct.

Question 17

An electron in the hydrogen atom makes a transition from the state to an nth state.The electron gains 0.50 eV of energy.What value of is the final state of the electron?

A)0
B)2
C)4
D)6
E)8

Question 18

The period of rotation of electron on the second Bohr orbit is

A)0.608 fs.
B)1.22 fs.
C)3.67 fs.
D)4.53 fs.
E)5.34 fs.

Question 19

The maximum orbital angular momentum quantum number for the is

A)0.
B)1.
C)2.
D)3.
E)4.

Question 20

In the Bohr model of hydrogen,as the principle quantum number n increases,

A)the total energy increases and the kinetic energy decreases.
B)the potential energy increases and the speed decreases.
C)the orbital radius increases.
D)All are correct.

Question 21

A group of hydrogen-like atoms (atoms with only one electron)are in their ground state.Light of increasing intensity is shone at these atoms until the light becomes absorbed by the atoms.The longest wavelength of light when this occurs is 7.61 nm.What is the ground state energy of these atoms?

A)91.8 eV
B)13.6 eV
C)218 eV
D)122 eV
E)54 eV

Question 22

Find the wavelength of light emitted by a hydrogen atom when its electron makes the transition from the n = 5 state to the n = 2 state.

A)434 nm
B)652 nm
C)397 nm
D)486 nm
E)404 nm

Question 23

How many wave functions (different combinations of l and m)are possible in the n = 6 level of hydrogen?

A)6
B)26
C)30
D)36
E)720

Question 24

What is the longest possible wavelength that a hydrogen atom will emit?

A)91 nm
B)122 nm
C)365 nm
D)1459 nm
E)There is no limit.

Question 25

The muon has the same charge as an electron but has a mass that is 207 times greater.The negatively charged muon can bind to a proton to form a new type of hydrogen atom.How does the energy of a muon in the first excited state E_m1 of a muonic hydrogen atom compare with the energy of an electron in the first excited state E_e1of a conventional hydrogen atom?

A)|E_m1| $\approx$ |E_e1|
B)|E_m1| $\approx$ 100|E_e1|
C)|E_m1| $\approx$ |E_e1|/100
D)|E_m1| $\approx$ 200|E_e1|
E)|E_m1| $\approx$ |E_e1|/200

Question 26

The Pfund series results from emission/absorption of photons due to transitions of electrons in a hydrogen to/from the n=5 energy level from/to higher energy levels.What is the shortest wavelength photon emitted in the Pfund series?

A)658 nm
B)2.29 µm
C)2.74 µm
D)3.68 µm
E)12.4 µm

Question 27

For an electron in the ground state of a hydrogen atom,what is the probability of finding that electron within a Bohr radius of the proton? The ground state wave function for hydrogen is .

A)0.124
B)0.261
C)0.323
D)0.626
E)0.752

Question 28

The frequency of rotation of electron on the second Bohr orbit is

A)3.67 * 10¹⁴ Hz
B)8.20 * 10¹⁴ Hz
C)9.03 * 10¹⁴ Hz
D)6.44 * 10¹⁴ Hz
E)1.27 * 10¹⁵ Hz

Question 29

A hydrogen atom is in a quantum state with principal quantum number n = 3.The atom emits a photon with a wavelength of 660 nm.Determine the maximum possible orbital angular momentum of the electron after emission.

A)
B)
C)
D)
E)

Question 30

A group of hydrogen-like atoms (atoms with only one electron)are in their ground state.Light of increasing intensity is shone at these atoms until the light becomes absorbed by the atoms.The lowest frequency of light when this occurs is 2.22 * 10¹⁶ Hz.What is the ground state energy of these atoms?

A)91.8 eV
B)13.6 eV
C)218 eV
D)122 eV
E)54 eV

Question 31

In a "muonic" atom an electron is replaced by a muon of mass 105.66 MeV which orbits a proton.What is the ground-state energy of the muon in this type of atom?

A)-281 eV
B)-632 eV
C)-1264 eV
D)-2528 eV
E)-3254 eV

Question 32

The Pfund series results from emission/absorption of photons due to transitions of electrons in a hydrogen to/from the n=5 energy level from/to higher energy levels.What is the longest wavelength photon emitted in the Pfund series?

A)658 nm
B)2.29 µm
C)2.74 µm
D)7.47 µm
E)12.4 µm

Question 33

A group of hydrogen-like atoms (atoms with only one electron)are in their ground state.Light of increasing intensity is shone at these atoms until the light becomes absorbed by the atoms.The lowest energy of light when this occurs has energy of 40 eV.What is the ground state energy of these atoms?

A)10 eV
B)13.6 eV
C)30 eV
D)40 eV
E)53 eV

Question 34

A hydrogen atom is in a quantum state with principal quantum number n = 2.The atom absorbs a photon with a wavelength of 660 nm.Determine the maximum possible orbital angular momentum of the electron after absorption.

A)
B)
C)
D)
E)

Question 35

A hydrogen atom is in a quantum state with principal quantum number n = 9.The atom emits a photon and after emission its principal quantum number becomes 2.The wavelength of the emitted photon is

A)384 nm.
B)420 nm.
C)557 nm.
D)620 nm.
E)701 nm.

Question 36

A hydrogen atom relaxes to a lower energy state by emitting a 2.55 eV photon.What is the lower energy state?

A)n = 1
B)n = 2
C)n = 3
D)n = 4
E)n = 5

Question 37

He⁺ is a helium atom with one electron missing.Treating this like a hydrogen atom,what is the first excited state of this atom?

A)-6.40 eV
B)-13.6 eV
C)-54.4 eV
D)-76.8 eV
E)-152.2 eV

Question 38

A laser (with wavelength of )excites the electron in a hydrogen atom from its ground state to its first excited state.What laser wavelength is required to raise the electron from the first excited state to its next lowest excited state?

A)
B)
C)
D)
E)

Question 39

The angular frequency of rotation of electron on the second Bohr orbit is

A)3.67 * 10¹⁵ rad/sec
B)4.98 * 10¹⁵ rad/sec
C)5.34 * 10¹⁵ rad/sec
D)5.17 * 10¹⁵ rad/sec
E)5.71 * 10¹⁵ rad/sec

Question 40

Find the frequency of light emitted by a hydrogen atom when its electron makes the transition from the n = 5 state to the n = 2 state.

A)2.3 * 10⁶ Hz
B)1.1 * 10⁷ Hz
C)6.9 * 10¹⁴ Hz
D)3.3 * 10¹⁵ Hz
E)3.8 * 10¹⁵ Hz

Question 41

What is the energy of the orbiting electron in a hydrogen atom with a quantum number of 45?

A)+3.8 * 10^-3 eV
B)-4.2 * 10^-3 eV
C)-6.7 * 10^-3 eV
D)+4.5 * 10^-3 eV

Question 42

If the energy of the orbiting electron in a hydrogen atom is -9.93 * 10^-3 eV,what is its quantum number?

A)37
B)45
C)98
D)1370

Question 43

A photon of wavelength 1.17 $\mu$ m is emitted by a He⁺ when the electron jumps from the n = 7 state.What is the final state of the electron?

A)1
B)2
C)3
D)4
E)5

Question 44

A UV laser emits light that has a wavelength 350 nm.If 1.23 * 10¹⁸ photons are emitted in 10 ns,what is the power of the laser?

A)77 MW
B)92 MW
C)83 MW
D)70 MW
E)5.0 MW

Question 45

What is the angular momentum of the orbiting electron in a hydrogen atom with quantum number of 45?

A)0.4 * 10^-31 kg m²/s
B)1.6 * 10^-31 kg m²/s
C)2.3 * 10^-33 kg m²/s
D)4.7 * 10^-33 kg m²/s

Question 46

Find the energy difference between an excited state and the ground state of a system where the population ratio of the excited state to the ground state is 2.9 * 10^-4.The temperature of the system is 300 K.

A)0.200 eV
B)0.191 eV
C)0.211 eV
D)0.223 eV

Question 47

What is the energy of the photon required to knock the electron out of a singly ionized Helium atom where the electron was in the n = 4 state?

A)3.4 eV
B)1.7 eV
C)10.2 eV
D)51 eV

Question 48

What is the wavelength of the photon emitted by a He⁺ when the electron jumps from the n = 7 to the n = 4 state?

A)8.8 $\mu$ m
B)3.4 $\mu$ m
C)4.4 $\mu$ m
D)896 nm
E)542 nm

Question 49

The energy difference between an excited state and the ground state of a system is 0.2 eV.If the population ratio of the excited state to the ground state is 2.9 * 10^-4,what is the temperature of the system?

A)300 K
B)330 K
C)285 K
D)315 K

Question 50

A 5.0 MW UV laser emits light that has a wavelength 350 nm.If the duration of the pulse is 10 ns,how many photons are there in each pulse?

A)8.8 * 10¹⁶
B)12.3 * 10¹⁸
C)62.5 * 10²⁰
D)89.1 * 10²⁰

Question 51

What is the longest wavelength in the Lyman series of hydrogen?

A)122 nm
B)312 nm
C)415 nm
D)535 nm

Question 52

In the Bohr hydrogen atom,how many antinodes are there in the electron standing wave with a quantum number of 6?

A)12
B)6
C)3
D)5

Question 53

A photon of wavelength 155 nm is absorbed by the electron in a hydrogen atom that was in the n = 2 state.What is the energy of the electron as it leaves the atom?

A)4.6 eV
B)1.2 eV
C)5.6 eV
D)2.2 eV

Question 54

Identify the element that has the configuration 1s²2s²2p⁶3s²3p⁶3d⁸4s².

A)Fe
B)Ni
C)Co
D)Au

Question 55

Krypton has 36 electrons.What is the expected orbital angular momentum quantum number of the outermost electron for Krypton in its first excited state?

A)l = 0
B)l = 1
C)l = 2
D)l = 3
E)l = 4

Question 56

The radial probability density of a hydrogen atom tells the relative likelihood of finding the electron at a distance r from the nucleus.If a_o is the Bohr radius,where is the electron in the 2p state most likely to be found?

A)r = a_o
B)r = 2a_o
C)r = 3a_o
D)r = 4a_o

Question 57

A 5.0 UV laser emits light that has a wavelength 350 nm.If 1.23 * 10¹⁸ photons are emitted in a pulse,what is the duration of the pulse?

A)140 ns
B)89 ns
C)54 ns
D)110 ns
E)10 ns

Question 58

What are the quantum numbers n and l for a hydrogen atom with E = - (13.6/16)eV and L = $\sqrt6$ ?

A)n = 4,l = 2
B)n = 4,l = 6
C)n = 3,l = 3
D)n = 3,l = 6

Question 59

In a system where the energy difference between the excited state and the ground state is 0.2 eV,what is the population ratio of the excited state relative to the ground state at a temperature of 300 K?

A)4.4 * 10^-4
B)2.9 * 10^-4
C)1.02
D)0.001

Question 60

A photon of wavelength 1.17 $\mu$ m is emitted by a He⁺ when the electron jumps to the n = 5 state.What was the initial state of the electron,prior to the jump?

A)6
B)7
C)8
D)9
E)10

Question 61

What is the shortest wavelength photon that can be emitted by singly ionized helium (He⁺)?

A)23 nm
B)46 nm
C)54 nm
D)91 nm
E)365 nm

Question 62

About how many photons are emitted per second by a yellow (600 nm)60-mW laser?

A)2 * 10¹⁵
B)3 * 10¹⁹
C)3 * 10¹⁸
D)2 * 10¹²
E)2 * 10¹⁷

Question 63

How many electrons are allowed to inhabit the M-shell of an atom?

A)18
B)10
C)8
D)32
E)14

Question 64

What is the angular momentum of an electron in an l = 4 level of the correct quantum mechanical hydrogen atom?

A)1/2 Js
B)0.5 * 10⁵ Js
C)0.1 * 10²⁵ Js
D)6.6 * 10^-23 Js
E)4.6 * 10^-34 Js

Question 65

How much energy does a photon need to lift an electron from the n = 2 to the n = 8 level in the hydrogen atom?

A)1.0 eV
B)3.19 eV
C)7.2 eV
D)13.6 eV
E)22.4 eV

Question 66

An excited hydrogen atom emits a photon with an energy of 0.661 eV.What was the initial state of the hydrogen atom before emitting the photon?

A)n = 1
B)n = 2
C)n = 3
D)n = 4
E)n = 5

Question 67

What is the magnitude (in N)of the electric force between a proton and a (lowest energy)n = 1 electron in a hydrogen atom?

A)8.2 * 10^-8
B)8.2 * 10⁸
C)8.2 * 10^-12
D)8.2 * 10^-4
E)8.2 * 10⁴

Question 68

A hydrogen atom in its ground state absorbs a photon of energy 12.75 eV.What is its new value of n,the main quantum number in the Bohr model?

A)1
B)2
C)3
D)4
E)5

Question 69

A collection of hydrogen atoms has been placed into the n = 4 excited state.Which of the following wavelengths of photons will NOT be emitted by the hydrogen atoms as they decay back to the ground state?

A)97 nm
B)490 nm
C)970 nm
D)1900 nm

Question 70

What is the radius of the n = 7 level of the Bohr hydrogen atom?

A)2.6 nm
B)9.3 nm
C)0.53 nm
D)0.053 nm
E)0.37 nm

Question 71

An excited hydrogen atom emits a photon with an energy of 0.661 eV.What was the final state of the hydrogen atom after emitting the photon?

A)n = 1
B)n = 2
C)n = 3
D)n = 4
E)n = 5

Question 72

For ,which value of m corresponds to a wave function that has its maximum probability in the x-y plane?

A)l = 3,m = 0
B)l = 3,m = 1
C)l = 3,m = 2
D)l = 3,m = 3
E)l = 3,m = 4