Deck 12: Quantum Mechanics and Atomic Theory

Question 1

Which of the following statements is(are) true?
I. An excited atom can return to its ground state by absorbing electromagnetic radiation.
II. The energy of an atom is increased when electromagnetic radiation is emitted from it.
III. The energy of electromagnetic radiation increases as its frequency increases.
IV. An electron in the n = 4 state in the hydrogen atom can go to the n = 2 state by emitting electromagnetic radiation at the appropriate frequency.
V. The frequency and wavelength of electromagnetic radiation are inversely proportional to each other.

A) III, V
B) II, III, IV
C) I, II, IV
D) I, II, III
E) III, IV, V

Answer 1

III, IV, V

Question 2

From the following list of observations, choose the one that most clearly supports the conclusion that electrons in atoms have quantized energies.

A) the photoelectric effect
B) the scattering of alpha particles by metal foil
C) diffraction
D) cathode "rays"
E) the emission spectrum of hydrogen

Answer 2

the emission spectrum of hydrogen

Question 3

Which of the following frequencies corresponds to light with the longest wavelength?

A) 9.12 *10¹² s^-1
B) 3.20 * 10⁹ s^-1
C) 8.50 * 10²⁰ s^-1
D) 3.00 *10¹³ s^-1
E) 4.12 * 10⁵ s^-1

Answer 3

4.12 * 10⁵ s^-1

Question 4

From the following list of observations, choose the one that most clearly supports the conclusion of de Broglie wavelengths.

A) cathode "rays"
B) the scattering of alpha particles by metal foil
C) diffraction
D) the emission spectrum of hydrogen
E) the photoelectric effect

Question 5

In Bohr's atomic theory, when an electron moves from one energy level to another energy level more distant from the nucleus,

A) energy is emitted.
B) energy is absorbed.
C) light is emitted.
D) no change in energy occurs.
E) none of these

Question 6

Light has a wavelength of 5.8 *10² nm. What is the energy of a photon of this light?

A) 2.62 *10¹⁸ J
B) 3.81 * 10^-20 J
C) 1.28 * 10^-18 J
D) 1.14 *10^-19 J
E) 3.42 * 10^-19 J

Question 7

Consider an atom traveling at 1% of the speed of light. The de Broglie wavelength is found to be 3.31 *10^-3 pm. Which element is this?

A) P
B) Ca
C) He
D) F
E) Be

Question 8

Which form of electromagnetic radiation has the shortest wavelengths?

A) gamma rays
B) X rays
C) radio waves
D) microwaves
E) infrared radiation

Question 9

From the following list of observations, choose the one that most clearly supports the conclusion that atoms contain electrons.

A) the emission spectrum of hydrogen
B) cathode "rays"
C) diffraction
D) the photoelectric effect
E) the scattering of alpha particles by metal foil

Question 10

From the following list of observations, choose the one that most clearly supports the conclusion that electrons have wave properties.

A) the scattering of alpha particles by metal foil
B) the photoelectric effect
C) the emission spectrum of hydrogen
D) diffraction
E) cathode "rays"

Question 11

A photographic film needs a minimum of 80.0 kJ/mol for exposure. What is the longest wavelength of radiation with sufficient energy to expose the film?

A) 1.50 * 10^-3 m
B) 1.50 *10^-12 m
C) 1.50 * 10^-6 m
D) 1.50 * 10^-9 m
E) none of these

Question 12

What is the wavelength of light that is emitted when an excited electron in the hydrogen atom falls from the n = 5 level to the n = 2 level?

A) 5.82 *10^-7 m
B) 6.50 * 10^-7 m
C) 4.34 *10^-7 m
D) 5.12*10^-7 m
E) none of these

Question 13

What is the wavelength, in nanometers, of a photon of light whose frequency is 5.38 *10¹⁴ Hz?

A) 1.19 * 10^-7 nm
B) 2.71 * 10² nm
C) 5.58 * 10² nm
D) 1.79 * 10² nm
E) 3.69 * 10² nm

Question 14

Consider the following portion of the energy-level diagram for hydrogen:
For which of the following transitions does the light emitted have the longest wavelength?

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

Question 15

In general, Z is less than Z_eff.

Question 16

A photographic film needs a minimum of 80.0 kJ/mol for exposure. The frequencies of visible light are in the range 7.5 * 10¹⁴ Hz to 4.3 * 10¹⁴ Hz. Is the radiation visible to the human eye?

A) yes
B) no
C) More information is needed.

Question 17

From the following list of observations, choose the one that most clearly supports the conclusion that the mass of the atom is located mainly in the nucleus.

A) the emission spectrum of hydrogen
B) the photoelectric effect
C) diffraction
D) the scattering of alpha particles by metal foil
E) cathode "rays"

Question 18

Which of the following is a reasonable criticism of the Bohr model of the atom?

A) It shows the electrons to exist outside of the nucleus.
B) It does not adequately predict the ionization energy of the first-energy-level electrons for elements other than hydrogen.
C) It makes no attempt to explain why the negative electron does not eventually fall into the positive nucleus.
D) It does not adequately predict the ionization energy of the valence electron(s) for elements other than hydrogen.
E) It does not adequately predict the line spectrum of hydrogen.

Question 19

In an investigation of the electronic absorption spectrum of a particular element, it is found that a photon having $\lambda$ = 500 nm provides just enough energy to promote an electron from the second quantum level to the third. From this information, we can deduce

A) the energy of the n = 2 level.
B) the sum of the energies of the n = 2 and n = 3 levels.
C) the difference between the energies of the n = 2 and n = 3 levels.
D) the energy of the n = 3 level.
E) all of these.

Question 20

From the following list of observations, choose the one that most clearly supports the conclusion that electromagnetic radiation has wave characteristics.

A) diffraction
B) the emission spectrum of hydrogen
C) the scattering of alpha particles by metal foil
D) cathode "rays"
E) the photoelectric effect

Question 21

Which of the following statements is true?

A) We can determine the exact location of an electron if we know its energy.
B) Ni has 2 unpaired electrons in its 3d orbitals.
C) An electron in a 2s orbital can have the same n, l, and m_l quantum numbers as an electron in a 3s orbital.
D) Only three quantum numbers are needed to uniquely describe an electron.
E) In the building up of atoms, electrons occupy the 4f orbitals before the 6s orbitals.

Question 22

How many electrons can be described by the quantum numbers n = 4, l = 4, m_l = 0?

A) 14
B) 6
C) 10
D) 0
E) 2

Question 23

The number of orbitals having a given value of l is equal to

A) the number of lobes in each orbital
B) 2n + 2
C) 3l
D) l + m_l
E) 2l + 1

Question 24

For an electron in a one-dimensional box, what is the minimum energy to excite the electron from the ground state?

A)
B)
C)
D)
E)

Question 25

Which of the following is not determined by the principal quantum number, n, of the electron in a hydrogen atom?

A) the minimum wavelength of the light needed to remove the electron from the atom.
B) the energy of the electron
C) the shape of the corresponding atomic orbital(s)
D) the size of the corresponding atomic orbital(s)
E) All of the above are determined by n.

Question 26

An electron in a 10.0-nm one-dimensional box is excited from the ground state into a higher energy state by absorbing a photon with wavelength 1.374 *10^-5 m. Determine the final energy level for this transition.

A) n = 6
B) n = 4
C) n = 2
D) n = 5
E) n = 3

Question 27

For an electron in a 2.00-nm one-dimensional box, calculate the wavelength of electromagnetic radiation to excite the electron from the ground state to the level with n = 3.

A) 12,100 nm
B) 1470 nm
C) 13,200 nm
D) 1650 nm
E) none of these

Question 28

How many electrons in an atom can have the quantum numbers n = 3, l = 2?

A) 18
B) 32
C) 2
D) 6
E) 10

Question 29

The energy equation for a particle in a cubic box of dimensions L_x = L_y = L_z is E_{nx, ny, nz} = For a particle in a cubic box, how many degenerate energy levels have energy equal to 14 h²/8 mL²?

A) 1
B) 12
C) 6
D) 8
E) 3

Question 30

What is the probability of finding a particle in a one-dimensional box in energy level n = 4 between x = L/4 and x = L/2? (L is the length of the box.)

A) 50%
B) 12.5%
C) 33%
D) 25%
E) 37.5%

Question 31

The wavelength of light associated with the n = 2 to n = 1 electron transition in the hydrogen spectrum is 1.216 * 10^-7 m. By what coefficient should this wavelength be multiplied to obtain the wavelength associated with the same electron transition in the Li²⁺ ion?

A) 1
B) 1/3
C) 1/4
D) 1/7
E) 1/9

Question 32

An electron in a one-dimensional box requires energy with wavelength 8080 nm to excite it from the n = 2 energy level to the n = 3 energy level. Calculate the length of the box.

A) 1.50 nm
B) 3.00 nm
C) 1.00 nm
D) 2.50 nm
E) 3.50 nm

Question 33

The energy expressions for the electrons in the He⁺ ion and the hydrogen atom are E_n (H) = -a/n² and E_n (He⁺) = -4a/n²
Which of the following statements is(are) correct?
I. For the transitions , the frequency is larger for H than for He+.
II. The first ionization energy of the H atom is smaller than the second.
III. The 1s orbital in He+ is larger (in the sense that the probability density is
shifted outward) than the 1s orbital in H.

A) III only
B) I and II only
C) I only
D) I, II, and III
E) II only

Question 34

Which of the following statements about quantum theory is incorrect?

A) No two electrons can have the same four quantum numbers.
B) The energy and position of an electron cannot be determined simultaneously.
C) Lower energy orbitals are filled with electrons before higher energy orbitals.
D) When filling orbitals of equal energy, two electrons will occupy the same orbital before filling a new orbital.
E) All of these are correct.

Question 35

On a planet where the temperature is so high, the ground state of an electron in the hydrogen atom is n = 4. What is the ratio of IE on this planet to that on earth?

A) 1:16
B) 1:4
C) 4:1
D) 16:1
E) 1:1

Question 36

Consider the following portion of the energy-level diagram for hydrogen:

-In the hydrogen spectrum, what is the wavelength of light associated with the n = 2 to n = 1 electron transition?

A) 0.1097*10^-8 cm
B) 364.9 nm
C) 9.122 * 10^-8 m
D) 1.097 nm
E) 1.216 *10^-7 m

Question 37

The ionization energy for a hydrogen atom is 1.31 *10⁶ J/mol. What is the ionization energy for He⁺?

A) 2.18 *10^-18 J/mol
B) 1.31 * 10⁶ J/mol
C) 5.25* 10⁶ J/mol
D) 8.72 * 10^-18 J/mol
E) 2.63 *10⁶ J/mol

Question 38

Which of the following combinations of quantum numbers is not allowed? (Combinations are listed as follows: n, l, m_(l), m_(s).)

A)
B)
C)
D) https://d2lvgg3v3hfg70.cloudfront.net/TB6420/.
E)

Question 39

How many electrons can be described by the quantum numbers n = 4, l = 3, m_l = 0?

A) 2
B) 10
C) 6
D) 0
E) 14

Question 40

How many electrons can be described by the quantum numbers n = 3, l = 1?

A) 5
B) 2
C) 3
D) 1
E) 6

Question 41

Which orbital has the highest energy in the rubidium atom?

A) 4p
B) 4s
C) 5s
D) 1s
E) 4d

Question 42

How many electrons can be contained in all of the orbitals with n = 4?

A) 8
B) 10
C) 2
D) 18
E) 32

Question 43

Of the following elements, which has occupied d orbitals in its ground-state neutral atoms?

A) Si
B) Ba
C) K
D) O
E) F

Question 44

In which orbital does an electron experience the highest Z_eff?

A) P (3p)
B) Na (3s)
C) Al (3p)
D) Mg (3s)
E) S (3p)

Question 45

An element E has the electron configuration [Ar]3d¹⁰4s²4p³. What is the formula for the fluoride of E most likely to be?

A) EF₆
B) EF₈
C) EF₃
D) EF
E) EF₂

Question 46

Which of the following statements is false?

A) In the usual order of filling, the 6s orbital is filled before the 4f orbital.
B) An orbital can accommodate at most two electrons.
C) The spin quantum number of an electron must be either +1/2 or -1/2.
D) A 2p orbital is more penetrating than a 2s; that is, it has a higher electron density near the nucleus and inside the charge cloud of a 1s orbital.
E) The electron density at a point is proportional to $\Psi$ ² at that point.

Question 47

What is the electron configuration of Cr³⁺?

A) [Ar] 4s²3d¹
B) [Ar] 3d³
C) [Ar] 4s²3d⁴
D) [Ar] 4s¹3d²
E) none of these

Question 48

What is the electron configuration for the barium atom?

A) 1s²2s²2p⁶3s²3p⁶4s²
B) 1s²2s²2p⁶3s²3p⁶4s¹
C) 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²
D) [Xe] 6s²
E) none of these

Question 49

Which is the highest occupied energy orbital in a silicon atom?

A) 3p
B) 3d
C) 3s
D) 2s
E) 1s

Question 50

What value is the closest estimate of Z_eff for a valence electron of the calcium atom?

A) 20
B) 40
C) 2
D) 6
E) 1

Question 51

How many electrons can be described by the quantum number n = 3?

A) 32
B) 2
C) 18
D) 8
E) 10

Question 52

How many electrons can be described by the quantum numbers n = 4, l = 3, m_l = -1, m_s = -1?

A) 0
B) 14
C) 2
D) 6
E) 10

Question 53

In which groups do all the elements have the same number of valence electrons?

A) N, P, As
B) P, As, Se
C) Ag, Cd, Ar
D) K, Mg, Ba
E) P, S, Cl

Question 54

How many f orbitals have the value n = 3?

A) 3
B) 1
C) 0
D) 5
E) 7

Question 55

Which of the following atoms or ions has 3 unpaired electrons?

A) Br^-
B) Ga
C) S
D) Co
E) Mg²⁺

Question 56

An element with the electron configuration [Xe]4f¹⁴5d⁷6s² would belong to which class on the periodic table?

A) transition elements
B) alkaline earth elements
C) rare earth elements
D) halogens
E) none of these

Question 57

Which of the following combinations of quantum numbers do not represent permissible solutions of the Schrodinger equation for the electron in the hydrogen atom? (In other words, which combination of quantum numbers is not allowed?) (Combinations are listed as follows: n, l, m_(l), m_(s).)

A) 6 5 -5 1/2
B) All are allowed.
C) 8 2 2 1/2
D) 9 8 -4 1/2
E) 6 -5 -1 1/2

Question 58

What is the electron configuration of the element with atomic number 113?

A) [Rn] 7s²5f¹⁴7d¹⁰7p¹
B) [Rn] 7s²7f¹⁴7d¹⁰7p¹
C) [Rn] 7s²6d¹⁰7p¹
D) [Rn] 7s²5f¹⁴6d¹⁰7p¹
E) none of these

Question 59

Of the following elements, which needs 3 electrons to complete its valence shell?

A) S
B) Ba
C) K
D) N
E) F

Question 60

The first ionization energy of Mg is 735 kJ/mol. Calculate Z_eff.

A) 2.25
B) 2.00
C) 4.00
D) 5.04
E) none of these

Question 61

For which of the following elements does the electron configuration for the lowest energy state show a partially filled d orbital?

A) S
B) Ca
C) Rb
D) Kr
E) Ti

Question 62

What is the electron configuration for Cr²⁺?

A) [Ar] 4s¹3d⁵
B) [Ar] 4s²3d⁴
C) [Ar] 4s²3d²
D) [Ar] 3d⁴
E) none of these

Question 63

What is the electron configuration of Ti²⁺?

A) [Ar] 3d²
B) [Ar] 4s²
C) [Ar] 4s¹3d¹
D) [Ar] 4s²3d²
E) none of these

Question 64

How many of the following electron configurations for the species in their ground state are correct?

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

Question 65

Which atom has three 2p electrons in its ground state?

A) Si
B) As
C) N
D) P
E) none of these

Question 66

How many unpaired electrons are there in an atom of sulfur in its ground state?

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

Question 67

Which of the following atoms has 3 electrons in p orbitals in its valence shell?

A) Ba
B) Ga
C) Bi
D) V
E) none of these

Question 68

What is the electron configuration of Co³⁺?

A) [Ar] 3d⁶
B) [Ar] 4s²4d⁴
C) [Ar] 3d⁴
D) [Ar] 4s²3d⁴
E) none of these

Question 69

How many unpaired electrons does chlorine have in its ground state?

A) 2
B) 3
C) 17
D) 1
E) none of these

Question 70

What is the total number of electrons that can be accommodated in the level corresponding to n = 5?

A) 32
B) 2
C) 50
D) 8
E) 18

Question 71

The number of unpaired electrons in the outer subshell of a Cl atom is

A) 0
B) 1
C) 3
D) 2
E) none of these

Question 72

An atom of nitrogen contains 7 electrons. How many of these electrons are in p orbitals?

A) 3
B) 6
C) 10
D) 2
E) 8

Question 73

How many unpaired electrons does arsenic have in its ground state?

A) 33
B) 3
C) 1
D) 2
E) none of these

Question 74

For which element are the d orbitals completely filled in the neutral atom?

A) bromine
B) phosphorus
C) potassium
D) vanadium
E) iron

Question 75

What is the valence electron configuration of S?

A) 3s²3p⁴
B) 4s²4p⁴
C) 1s²2s²2p⁶3s²3p⁴
D) 1s²2s²2p⁴
E) none of these

Question 76

What is the electron configuration for the chromium atom?

A) [Kr] 4s¹3d⁵
B) [Ar] 4s²3d⁴
C) [Kr] 4s²3d⁴
D) [Ar] 4s¹3d⁵
E) none of these

Question 77

How many valence electrons do the alkaline earth metals have?

A) 8
B) 2
C) 7
D) 3
E) 1

Question 78

Which of the following electron configurations is correct?

A) Ca: [Ar]4s¹3d¹⁰
B) Mo: [Kr]5s²4d⁵
C) Br: [Kr]3d¹⁰4s²4p⁷
D) Bi: [Xe]6s²4f¹⁴5d¹⁰6p³
E) Ga: [Kr]3d¹⁰4s²4p¹

Question 79

What is the electron configuration of indium?

A) 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4d¹⁰4p¹
B) 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶4d¹⁰5s²5p¹5d¹⁰
C) 1s²3s²2p⁶3s²3p⁶4s²4p⁶4d¹⁰5s²5d¹⁰5p¹
D) 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶4d¹⁰5s²5p¹
E) none of these

Question 80

An element has the electron configuration [Kr] 4d¹⁰5s²5p². The element is a(n)

A) actinide.
B) metal.
C) transition element.
D) lanthanide.
E) nonmetal.