Deck 41: Atomic Physics

Question 1

Consider the four quantum numbers of an electron in an atom, n, l, m_l, and m_s. The energy of an electron in an isolated atom depends on

A) n only.
B) n and l only.
C) n, l, and m_l only.
D) l, m_l, and m_s only.
E) all four quantum numbers.

Answer 1

n only.

Question 2

The magnitude of the orbital angular momentum L of an electron in a certain atom is equal to 3.464ħ. Which one of the following numbers could be the principal quantum number n of the electron?

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

Answer 2

4

Question 3

If an electron has spin quantum number m_s = - what is the possible value for the orbital quantum number l of the electron?

A) 0
B) 1
C) 2
D) 11
E) All of the above numbers are possible.

Answer 3

All of the above numbers are possible.

Question 4

What is the greatest magnitude of the orbital angular momentum L for an electron in a state with principal quantum number n = 5?

A) 4.47
B) 4.90
C) 5
D) 5.48

Question 5

How fast must a hydrogen atom be traveling for its kinetic energy to be just enough to excite the ground-state atom to its first excited state in a collision? (1 eV = 1.60 × 10^-19 J, m_h ≈ m_proton =
1.67 × 10^-27 kg)

A) 44.2 km/s
B) 21.7 km/s
C) 66.5 km/s
D) 113 km/s
E) 51.0 km/s

Question 6

An electron in a hydrogen atom has orbital quantum number l = 4. How many possible values of the magnetic quantum number m_l could it have?

A) 4
B) 10
C) 5
D) 9
E) 3

Question 7

For each value of the principal quantum number n, what are the possible values of the electron spin quantum number m_s? (There may be more than one correct choice.)

A) 0
B) +1/2
C) -1/2
D) +3/2
E) -3/2

Question 8

An electron in a hydrogen atom has orbital quantum number l = 7. How many possible values of the magnetic quantum number m_l could it have?

A) 6
B) 7
C) 15
D) 33
E) 98

Question 9

The normalized wave function for a hydrogen atom in the 1s state is given by ψ(r) = e^-r/α₀ where α₀ is the Bohr radius, which is equal to 5.29 × 10^-11 m. What is the probability of finding the electron at a distance greater than 7.8 α₀ from the proton?

A) 2.3 × 10^-5
B) 1.2 × 10^-5
C) 1.7 × 10^-5
D) 4.6 × 10^-5
E) 3.5 × 10^-5

Question 10

The magnitude of the orbital angular momentum L of an electron in a certain atom is equal to 3.464ħ. Which of the following angles could NOT be the angle between the orbital angular momentum vector of the electron and an arbitrary z-direction?

A) 107°
B) 90.0°
C) 73.2°
D) 54.7°
E) 0.00°

Question 11

The magnitude of the orbital angular momentum L of an electron in a certain atom is equal to 3.464ħ. What is the orbital quantum number l of the electron?

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

Question 12

The binding energy of the hydrogen atom in its ground state is -13.6 eV. What is the energy when it is in the n = 5 state?

A) 2.72 eV
B) -2.72 eV
C) 0.544 eV
D) -0.544 eV
E) -68 eV

Question 13

In the ground state, the quantum numbers (n, l, m_l, m_s) for hydrogen are, respectively

A) 1, 1, 1, 1
B) 1, 0, 0, 0
C) 1, 0, 0, ±
D) 1, 1, 1, ±
E) 1, 1, 0, ±

Question 14

If the orbital quantum number is l = 4, which one of the following is a possible value for the principal quantum number n?

A) 1
B) 2
C) 3
D) 4
E) 8

Question 15

An electron in a hydrogen atom has principal quantum number n = 4. How many possible values of the orbital quantum number l could it have?

A) 8
B) 9
C) 3
D) 4
E) 10

Question 16

An electron in a hydrogen atom is in the n = 7 shell. How many possible values of the orbital quantum number l could it have?

A) 6
B) 7
C) 15
D) 33
E) 98

Question 17

Which of the following are characteristics of laser light? (There may be more than one correct choice.)

A) It is coherent.
B) It is produced by an inverted population of atoms.
C) It contains a full spectrum of wavelengths.

Question 18

If the principal quantum number of an electron is n = 5, which one of the following is NOT an allowed magnetic quantum number m_l for the electron?

A) 0
B) 2
C) 3
D) 4
E) 5

Question 19

What is the minimum speed needed by a ground-state hydrogen atom for its kinetic energy to be enough to ionize the atom in a collision? (1 eV = 1.60 × 10^-19 J, m_h ≈ m_proton = 1.67 × 10^-27 kg)

A) 44.2 km/s
B) 21.7 km/s
C) 66.5 km/s
D) 113 km/s
E) 51.0 km/s

Question 20

What is the energy of an incident photon that is just enough to excite a hydrogen atom from its ground state to its n = 4 state?

A) 12.75 eV
B) 10.20 eV
C) 3.40 eV
D) 0.85 eV

Question 21

The correct ground state electron configuration of boron, which has 5 electrons, is

A) 1s²2s²2p.
B) 1s²2s²2p³.
C) 1s²1p²2s.
D) 1s²2p²3s.
E) 1s²2p³.

Question 22

Consider the n = 9 shell.
(a) What is the largest value of the orbital quantum number, l, in this shell?
(b) How many electrons can be placed in this shell?

Question 23

What is the electron configuration for ground state Li, which has 3 electrons?

A) 1s³
B) 1s¹2s²
C) 1s²2s¹
D) 1s²1p¹
E) 1s¹1p²

Question 24

A collection of atoms has 20% of the sample in a state 5.9 eV above the ground state. If these emit coherent radiation, what is the wavelength of the laser light produced? (c = 3.00 × 10⁸ m/s,
H = 6.626 × 10^-34 J ∙ s, 1 eV = 1.60 × 10^-19 J)

A) 210 nm
B) 91 nm
C) 340 nm
D) 34 nm

Question 25

How many electrons can be found with principal quantum number n = 3 in a suitably heavy atom?

A) 18
B) 6
C) 20
D) 9

Question 26

You need 14 W of infrared laser light power with wavelength 1270 nm to bore a hole in a diamond. How many downward atomic transitions per second must occur in the laser if all of them result in light directed onto the diamond? (c = 3.00 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s)

A) 8.9 × 10¹⁹
B) 8.9 × 10¹⁸
C) 5.9 × 10¹⁹
D) 2.7 × 10¹⁸

Question 27

In a ruby laser, an electron jumps from a higher energy level to a lower one. If the energy difference between the two levels is 1.8 eV, what is the wavelength of the emitted photon?
(c = 3.00 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s, 1 eV = 1.60 × 10^-19 J)

A) 350 nm
B) 470 nm
C) 650 nm
D) 690 nm
E) 960 nm

Question 28

A neutral atom has an electron configuration of 1s²2s²2p⁶3s²3p². How many protons does it have in its nucleus?

A) 5
B) 11
C) 14
D) 20
E) 26

Question 29

An atom with 5 electrons is in its ground state. How many electrons are in its outermost shell?

Question 30

How many electrons does it take to fill the d subshell?

A) 10
B) 6
C) 14
D) 4
E) 8

Question 31

The only VALID electron state and shell designation among the following is

A) 1p, K.
B) 2s, K.
C) 1s, L.
D) 2p, L.
E) 3f, M.

Question 32

What is the correct electronic configuration for ground state carbon, which has 6 electrons?

A) 1s²2s²2p²
B) 1s¹2p¹
C) 1s¹2s²2p¹
D) 1s¹2s¹2p¹
E) 1s²2s²2p⁴

Question 33

What is the correct electronic configuration for the ground state sodium atom, which has 11 electrons?

A) 1s¹2s²3p⁶2s²
B) 1s²2s¹3p⁶2s²
C) 1s¹2s²2p⁶
D) 1s²2s²2p⁶3s²
E) 1s²2s²2p⁶3s¹

Question 34

The only INVALID electron state and shell designation among the following is

A) 1s, K.
B) 2s, L.
C) 2d, L.
D) 3s, M.
E) 3d, M.

Question 35

An atom has completely filled inner shells and a single valence electron in an excited p state. The filled inner shells have an orbital momentum equal to zero. A magnetic field is applied, defining the z-axis along the field. Which of the following sets of angles are possible angles between the magnetic field and the orbital angular momentum?

A) 45°
B) 90°
C) 45°, 90°
D) 45°, 135°
E) 45°, 90°, 135°

Question 36

The wavelength of a ruby laser is 694.3 nm. What is the energy difference between the two energy states involved in laser action? (c = 2.9979 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s, 1 eV = 1.6022 × 10^-19 J)

A) 1.537 eV
B) 1.646 eV
C) 1.786 eV
D) 1.812 eV
E) 3.572 eV

Question 37

How many possible sets of quantum numbers (electron states) are there in the 5f subshell?

A) 2
B) 6
C) 8
D) 10
E) 14

Question 38

An atom has completely filled inner shells and a single valence electron in an excited p state. The filled inner shells have an orbital momentum equal to zero. What is the magnitude of the orbital angular momentum L of the atom?

A) 1.0ħ
B) 1.2ħ
C) 1.4ħ
D) 1.7ħ
E) 2.0ħ

Question 39

How many photons per second emerge from a laser of power 2.00 mW with wavelength 605 nm?
(c = 3.00 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s)

A) 6.09 × 10¹⁵ photons/s
B) 5.03 × 10¹² photons/s
C) 3.07 × 10¹⁵ photons/s
D) 3.07 × 10¹³ photons/s