Deck 38: Spectral Lines, Bohrs Theory, and Quantum Mechanics

Question 1

The new theory of motion that governs the realm of subatomic particles is called

A) general relativity.
B) thermodynamics.
C) quantum mechanics.
D) special relativity.

Answer 1

quantum mechanics.

Question 2

The light emitted from a collection of identical atoms produces not a continuous spectrum, but rather discrete wavelengths called

A) spectral lines.
B) a blackbody spectrum.
C) gamma rays.
D) whitebody rays.

Answer 2

spectral lines.

Question 3

The absorption of certain wavelengths of white light produces dark lines in the spectrum. These dark lines are called

A) Airy lines.
B) Fraunhofer lines.
C) Rydberg lines.
D) polarization lines.

Answer 3

Fraunhofer lines.

Question 4

The shortest possible wavelength of the spectral lines in the Paschen series is

A) 785 nm.
B) 862 nm.
C) 821 nm.
D) 762 nm.

Question 5

An electron in the Bohr model is in an $n = 1$ state. Its angular momentum is

A) $2.11 \times 10 ^ { - 34 }$ J.s.
B) $1.06 \times 10 ^ { - 34 }$ J.s.
C) $3.17 \times 10 ^ { - 34 }$ J.s.
D) $4.17 \times 10 ^ { - 34 }$ J.s.

Question 6

An electron in the Bohr model is in an $n = 2$ state. The radius of the electron is

A) $a _ { 0 }$
B) $2 a _ { 0 }$
C) $3 a _ { 0 }$
D) $4 a _ { 0 }$

Question 7

An electron in the Bohr model is in an $n = 2$ state. Its energy level is

A) -3.4 eV.
B) -6.8 eV.
C) -13.6 eV.
D) -9.2 eV.

Question 8

An electron in the Bohr model is in an $n = 3$ state. The electron then jumps down to the $n = 1$ state and gives off a photon of wavelength

A) 412 nm.
B) 318 nm.
C) 103 nm.
D) 285 nm.

Question 9

A jogger of mass 66 kg runs at a speed of 2.1 m/s. The de Broglie wavelength of the jogger is

A) $6.5 \times 10 ^ { - 34 }$ m.
B) $8.2 \times 10 ^ { - 35 }$ m.
C) $$1.2 \times 10 ^ { - 35 }$$ m.
D) $4.8 \times 10 ^ { - 36 }$ m.

Question 10

An electron has energy of 105 eV. The frequency associated with this electron is

A) $1.5 \times 10 ^ { 15 }$ Hz.
B) $2.5 \times 10 ^ { 16 }$ Hz.
C) $7.4 \times 10 ^ { 15 }$ Hz.
D) $6.6 \times 10 ^ { 16 }$ Hz.

Question 11

Thomson's "plum pudding" model, and electromagnetic theory, accounted for all of the following features of the atom except

A) the order of magnitude of the frequency of the emitted radiation.
B) the electrical neutrality.
C) the stability.
D) Hold it! There are no exceptions.

Question 12

Rutherford's nuclear model, and electromagnetic theory, accounted for all of the following features of the atom except

A) the order of magnitude of the frequency of the emitted radiation.
B) the electrical neutrality.
C) the stability.
D) Hold it! There are no exceptions.

Question 13

The general form of the frequencies of the spectral series for hydrogen is

A) $v \infty \left\{ \left( \frac { 1 } { n _ { 2 } } - \frac { 1 } { n _ { 1 } } \right) \right\}$
B) $\mathcal{v}$ $\infty\left\{\left(\frac{1}{n_{2}}\right)^{2}-\left(\frac{1}{n_{1}}\right)^{2}\right\}$ .

C) $\mathcal{v}$ $\infty\left\{\left(\frac{1}{n_{2}}\right)^{2}-\left(\frac{1}{n_{1}}\right)^{2}\right\}$


D) $\mathcal{v}$ $\infty \left\{ \left( n _ { 2 } \right) ^ { 2 } - \left( n _ { 1 } \right) ^ { 2 } \right\}$

Question 14

One of Bohr's postulates for hydrogen was that the electron and the proton were stable in the atom only if some quantity had a minimum value or some integer times that minimum value. That quantity was

A) energy.
B) charge.
C) angular momentum.
D) radius.

Question 15

For Bohr's atom, the lowest three energy levels (in eV) are approximately

A) -12, -3, -1.
B) -12, -6, -4.
C) -12, -24, -36.
D) -12, -48, -108.

Question 16

For the hydrogen atom, the radii of the first two excited states (in terms of the Bohr radius) are

A) 1/4, 1/9.
B) 1/2, 1/3.
C) 2, 3.
D) 4, 9.

Question 17

The approximate radius of the lowest Bohr orbit in the hydrogen atom is

A) 1/1000 angstrom.
B) an angstrom.
C) 1000 angstroms.
D) 1,000,000 angstroms.

Question 18

The approximate energy of the lowest Bohr orbit in the hydrogen atom is

A) 1/10 electron volt.
B) 1 electron volt.
C) 10 electron volts.
D) 100 electron volts.

Question 19

The shortest wavelength in the spectrum of the hydrogen atom is approximately

A) 1/1000 angstrom.
B) an angstrom.
C) 1000 angstroms.
D) 1,000,000 angstroms.

Question 20

A single electron in orbit around a helium nucleus (charge = +2, mass $\approx$ 4) has energy levels $E _ { \mathrm { He } }$ that are related to those for the electron orbiting a hydrogen nucleus ( $E _ { \mathrm { H } }$ ) by the relation

A) $E _ { \mathrm { He } } = 4 E _ { \mathrm { H } }$
B) $E _ { \mathrm { He } } = 2 E _ { \mathrm { H } }$
C) $E _ { \mathrm { He } } = \left( \frac { 1 } { 2 } \right) E _ { \mathrm { H } }$
D) $E _ { \mathrm { He } } = \left( \frac { 1 } { 4 } \right) E _ { \mathrm { H } }$

Question 21

The principal reason behind the correct response to the previous question is that

A) the charge of the helium nucleus is double that of the hydrogen nucleus.
B) the mass of the helium nucleus is four times that of the hydrogen nucleus.
C) Both of the first two responses are needed to account for the correct answer to the previous question.
D) Neither of the first two responses is needed to account for the correct answer to the previous question.

Question 22

Bohr's Correspondence Principle states that the results of quantum theory must agree with those obtained from classical theory

A) in the limit of large quantum numbers.
B) in the limit of small quantum numbers.
C) if the quantum numbers can be canceled from the equations.
D) Hold it! The correspondence principle does not insist upon agreement under any circumstances.

Question 23

The Heisenberg uncertainty relations apply to

A) photons.
B) electrons.
C) atoms.
D) all of the above.

Question 24

The energy levels in the hydrogen atom are related to the quantum number n by being proportional to

A) n².
B) n.
C) $\frac { 1 } { \mathrm { n } }$
D) $\frac { 1 } { n ^ { 2 } }$

Question 25

The radii of the electron orbits in the hydrogen atom are related to the quantum number n by being proportional to

A) n²
B) n.
C) $\frac { 1 } { \mathrm { n } }$
D) $\frac { 1 } { n ^ { 2 } }$

Question 26

The possible angular momentum of the electron in the hydrogen atom is related to the quantum number n by being proportional to

A) n².
B) n.
C) $\frac { 1 } { \mathrm { n } }$
D) $\frac { 1 } { n ^ { 2 } }$

Question 27

The formula for the de Broglie wavelength of a particle follows readily from the relations between energy E and frequency for light, frequency and wavelength for waves, and the specific relation between energy E and momentum p given in the equation

A) $E = p \mathrm { c }$ , for a photon.
B) $E = \frac { p ^ { 2 } } { 2 m }$ , for a Newtonian particle in motion.
C) $E ^ { 2 } = ( p c ) ^ { 2 } + \left( m c ^ { 2 } \right) ^ { 2 }$ , for a relativistic particle in motion.
D) $E = m \mathrm { c } ^ { 2 }$ , for a relativistic particle at rest.

Question 28

The de Broglie wavelength of a proton (which has a mass > than that of an electron) is

A) > the de Broglie wavelength of an electron.
B) $\approx$ the de Broglie wavelength of an electron.
C) < the de Broglie wavelength of an electron.
D) Hold it! No such generalization is valid.

Question 29

The de Broglie wavelength of an electron associated with a hydrogen atom in the ground state is

A) > the atomic radius.
B) $\approx$ the atomic radius.
C) < the atomic radius.
D) Hold it! Insufficient information is given to answer this question unambiguously.

Question 30

For the de Broglie wavelengths of an electron and of a proton to be equal, the electron must travel

A) much faster than the proton.
B) much slower than the proton.
C) at the same speed as the proton.
D) Hold it! Speed is irrelevant; mass is what counts.

Question 31

If the kinetic energy of an electron is quadrupled, its de Broglie wavelength is

A) quadrupled.
B) doubled.
C) halved.
D) quartered.

Question 32

Rutherford's nuclear model of the atom was devised to account for the experimental fact that charged particles that bombarded the atoms

A) ionized the atoms.
B) caused the atoms to recoil unexpectedly.
C) were themselves deflected through large angles.
D) None of the previous responses is valid.

Question 33

In Bohr's theory of the atom, the logical consequences of electromagnetic theory and classical mechanics are valid during

A) transitional processes.
B) stationary orbits.
C) Both of the first two responses are valid.
D) Neither of the first two responses is valid.

Question 34

Bohr's theory of the atom resulted in the quantization of all of the following physical parameters of the electron except

A) energy.
B) angular momentum.
C) radius.
D) Hold it! There are no exceptions.

Question 35

The radiation from stars that is in the form of spectral lines comes primarily from the

A) surface of the stars.
B) interior of the stars.
C) Both of the first two responses are valid.
D) Neither of the first two responses is valid.

Question 36

In the hierarchy of quantum numbers associated with the state of an atom, the order (from the highest-order number to the lowest-order number) is

A) magnetic (m), orbital (l), principal (n), spin (s).
B) principal (n), spin (s), magnetic (m), orbital (l).
C) principal (n), orbital (l), magnetic (m), spin (s).
D) orbital (l), principal (n), magnetic (m), spin (s).

Question 37

The energy of the stationary states of the hydrogen atom is determined principally by the quantum number

A) l.
B) m.
C) n.
D) s.

Question 38

The shape of the orbits for the stationary states of the hydrogen atom is determined principally by the quantum number

A) l.
B) m.
C) n.
D) s.

Question 39

The space quantization of the orbits for the stationary states of the hydrogen atom is determined principally by the quantum number

A) l.
B) m.
C) n.
D) s.

Question 40

The hyperfine structure of the spectrum associated with the stationary states of the hydrogen atom is determined principally by the quantum number

A) l.
B) m.
C) n.
D) s.

Question 41

Each of the following particles obeys the Pauli Exclusion Principle except

A) electron.
B) neutron.
C) photon.
D) proton.

Question 42

Particles obeying the Pauli Exclusion Principle have a spin of

A) 1/2.
B) 1
C) Both of the first two responses are valid.
D) Neither of the first two responses is valid.

Question 43

The similarities of chemicals having similar electron configurations include each of the following except

A) chemical activity.
B) atomic spectra.
C) atomic size.
D) Hold it! There are no exceptions.

Question 44

The phrase similar electron configurations in reference to different elements describes a similar

A) number of electrons in the outermost shell.
B) missing number of electrons in the outermost shell.
C) Either of the first two responses may be valid.
D) Neither of the first two responses is valid.

Question 45

Relative chemical activity is usually relatively high for atoms with an outer shell that is

A) almost full.
B) almost empty.
C) Both of the first two responses are valid.
D) Neither of the first two responses is valid.

Question 46

The numbers of available states for the n = 2 and the n = 3 shells are, respectively,

A) 2 and 8.
B) 8 and 18.
C) 10 and 26.
D) 10 and 28.

Question 47

The number of available states for the l = 4 subshell is

A) 4
B) 8
C) 9
D) 18

Question 48

The vibrational and the rotational states of molecules are both quantized. The parameters with allowed states that are integral multiples of the lowest state are, respectively,

A) angular momentum and energy.
B) energy and energy.
C) energy and angular momentum.
D) angular momentum and angular momentum.

Question 49

The transitions associated with allowed energy level changes for the vibrational and the rotational states of a specific molecular type involve frequencies that, respectively,

A) have a single value and have a single value.
B) have a single value and range over a spectrum.
C) range over a spectrum and have a single value.
D) range over a spectrum and range over a spectrum.

Question 50

The spacing of the energy levels for an excited atom and for a rotating molecule, as the level gets higher, is, respectively,

A) closer together and closer together.
B) closer together and farther apart.
C) farther apart and closer together.
D) farther apart and farther apart.

Question 51

The forbidden energies of free electrons in a conductor are a consequence of their de Broglie wavelengths, which result in all of the following except

A) the production of standing waves.
B) a partial reflection from lattice sites.
C) a partial transmission through lattice sites.
D) Hold it! There are no exceptions.