Deck 29: Molecules and Solids

Question 1

Choose the one alternative that best completes the statement or answers the question.
In its lowest quantum state, the energy of a diatomic harmonic oscillator having frequency $f$ is

A) $h f$ .
B) $3 h f / 2$ .
C) $h f / 2$ .
D) $h f / 4$ .

Answer 1

C

Question 2

Choose the one alternative that best completes the statement or answers the question.
For a diatomic quantum mechanical rotator, the energy difference between adjacent energy levels

A) decreases as L increases.
B) is constant for all L.
C) increases as L increases.
D) varies randomly as L increases.

Answer 2

C

Question 3

Choose the one alternative that best completes the statement or answers the question.
In its lowest quantum state, a diatomic quantum mechanical rotator has a rotational energy of

A) $\frac { \hbar ^ { 2 } } { 2 I }$
B) $\frac { \hbar ^ { 2 } } { I } .$
C) zero.
D) none of the given answers.

Answer 3

C

Question 4

Choose the one alternative that best completes the statement or answers the question.
In general, which of the following is usually the weakest bond?

A) covalent bond
B) hydrogen bond
C) van der Waals bond
D) ionic bond

Question 5

Choose the one alternative that best completes the statement or answers the question.
If a diatomic quantum mechanical vibrator in its ground state has energy E, what is its energy in its second state above the ground state?

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

Question 6

Choose the one alternative that best completes the statement or answers the question.
In general, which of the following is usually the strongest bond?

A) ionic bond
B) van der Waals bond
C) hydrogen bond

Question 7

Choose the one alternative that best completes the statement or answers the question.
Metallic bonding is due to

A) the sharing of electrons by all atoms.
B) atoms bonding to hydrogen molecules.
C) the transfer of electrons between atoms.
D) unequal charge distributions around neutral molecules.

Question 8

Choose the one alternative that best completes the statement or answers the question.
If a battery is connected to a diode with the positive terminal to the p side and the negative terminal to the n side, then diode is said to be

A) forward biased.
B) reversed biased.
C) Neither choice is correct.

Question 9

Choose the one alternative that best completes the statement or answers the question.
Ionic bonding is due to

A) the transfer of electrons between atoms.
B) the sharing of electrons between atoms.
C) atoms bonding to hydrogen molecules.
D) unequal charge distributions around neutral molecules.

Question 10

Choose the one alternative that best completes the statement or answers the question.
An n-type semiconductor is produced by

A) pure crystals of germanium.
B) doping the host crystal with acceptor impurities.
C) doping the host crystal with donor impurities.

Question 11

Choose the one alternative that best completes the statement or answers the question.
In a p-type semiconductor, a hole is

A) a missing atom in the crystalline structure.
B) an extra electron supplied by a donor atom.
C) a donor atom.
D) a region where an electron is missing.

Question 12

Choose the one alternative that best completes the statement or answers the question.
In a good conductor, the highest energy band containing electrons is

A) completely empty.
B) only partially filled.
C) completely filled.

Question 13

Choose the one alternative that best completes the statement or answers the question.
In a good insulator, the highest energy band containing electrons, called the valence band, is

A) completely filled.
B) only partially filled.
C) completely empty.

Question 14

Choose the one alternative that best completes the statement or answers the question.
A diatomic quantum mechanical rotator in the L = 1 quantum state has energy E. The same rotator in the L = 2 quantum state will have energy equal to

A) 3E.
B) 2E.
C) 6E.
D) none of the given answers.

Question 15

Choose the one alternative that best completes the statement or answers the question.
Van der Waals bonding is due to

A) atoms bonding to hydrogen molecules.
B) the sharing of electrons between atoms.
C) the transfer of electrons between atoms.
D) unequal charge distribution around neutral molecules.

Question 16

Choose the one alternative that best completes the statement or answers the question.
Covalent bonding is due to

A) atoms bonding to hydrogen molecules.
B) the sharing of electrons between atoms.
C) the transfer of electrons between atoms.
D) unequal charge distributions around neutral molecules.

Question 17

Choose the one alternative that best completes the statement or answers the question.
A simple junction transistor consists of three semiconductor sections consisting of

A) only pnp semiconductors.
B) either pnp or npn semiconductors.
C) only npn semiconductors.
D) none of the given combinations.

Question 18

Choose the one alternative that best completes the statement or answers the question.
A p-type semiconductor is produced by

A) doping the host crystal with acceptor impurities.
B) pure crystals of germanium.
C) doping the host crystal with donor impurities.

Question 19

Choose the one alternative that best completes the statement or answers the question.
For a diatomic quantum mechanical vibrator, the energy difference between adjacent quantum states

A) varies randomly as the integer v increases.
B) increases as the integer v increases.
C) decreases as the integer v increases.
D) is constant for all values of the integer v.

Question 20

Choose the one alternative that best completes the statement or answers the question.
When a voltage is applied across a p-type semiconductor, the holes

A) do not move.
B) are destroyed.
C) move toward the negative electrode.
D) move toward the positive electrode.

Question 21

Choose the one alternative that best completes the statement or answers the question.
Estimate the maximum rotational energy (in electron-volts) for a free and freely-spinning diatomic hydrogen molecule in the $L = 2$ quantum state. The equilibrium separation for the atoms in the $\mathrm { H } _ { 2 }$ molecule is $0.075 \mathrm {~nm} . \left( 1 \mathrm { eV } = 1.60 \times 10 ^ { - 19 } \mathrm {~J} , m _ { \text {proton } } = 1.67 \times 10 ^ { - 27 } \mathrm {~kg} , h = 6.626 \times 10 ^ { - 34 } \right.$ J.s)

A) $0.033 \mathrm { eV }$
B) $0.011 \mathrm { eV }$
C) $0.044 \mathrm { eV }$
D) $0.022 \mathrm { eV }$

Question 22

Choose the one alternative that best completes the statement or answers the question.
A diatomic molecule is vibrating in the $v = 1$ quantum state with a frequency of $2.0 \times 10 ^ { 13 } \mathrm {~Hz}$ . What is its vibrational energy? $\left( 1 \mathrm { eV } = 1.60 \times 10 ^ { - 19 } \mathrm {~J} , h = 6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } \right)$

A) $0.12 \mathrm { eV }$
B) $0.041 \mathrm { eV }$
C) $0.083 \mathrm { eV }$
D) $0.17 \mathrm { eV }$

Question 23

Choose the one alternative that best completes the statement or answers the question.
A diatomic molecule has $18 \times 10 ^ { - 5 } \mathrm { eV }$ of rotational energy in the $L = 2$ quantum state. What is its rotational energy in the $L = 0$ quantum state? $\left( 1 \mathrm { eV } = 1.60 \times 10 ^ { - 19 } \mathrm {~J} , h = 6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } \right)$

A) $6.0 \times 10 ^ { - 5 } \mathrm { eV }$
B) $9.0 \times 10 ^ { - 5 } \mathrm { eV }$
C) $0 \mathrm { eV }$
D) $3.0 \times 10 ^ { - 5 } \mathrm { eV }$

Question 24

Choose the one alternative that best completes the statement or answers the question.
The energy gap between the valence and conduction bands in a certain semiconductor is $1.25 \mathrm { eV }$ . What is the threshold wavelength for optical absorption in this substance? $\left( c = 3.00 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } , h = \right.$ $6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s }$ )

A) $994 \mathrm {~nm}$
B) $873 \mathrm {~nm}$
C) $599 \mathrm {~nm}$
D) $959 \mathrm {~nm}$

Question 25

Choose the one alternative that best completes the statement or answers the question.
A diatomic molecule has $2.6 \times 10 ^ { - 5 } \mathrm { eV }$ of rotational energy in the $L = 2$ quantum state. What is its rotational energy in the $L = 1$ quantum state? $\left( 1 \mathrm { eV } = 1.60 \times 10 ^ { - 19 } \mathrm {~J} , h = 6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } \right)$

A) $3.4 \times 10 ^ { - 6 } \mathrm { eV }$
B) $5.3 \times 10 ^ { - 6 } \mathrm { eV }$
C) $8.7 \times 10 ^ { - 6 } \mathrm { eV }$
D) $7.8 \times 10 ^ { - 6 } \mathrm { eV }$

Question 26

Choose the one alternative that best completes the statement or answers the question.
A diatomic quantum mechanical oscillator has a moment of inertia of $7.73 \times 10 ^ { - 45 } \mathrm {~kg} \cdot \mathrm { m } ^ { 2 }$ . What is the rotational energy when it is in the quantum state characterized by $L = 2$ ? $\left( 1 \mathrm { eV } = 1.60 \times 10 ^ { - 19 } \right.$ $\left. \mathrm { J } , h = 6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } \right)$

A) $8.71 \times 10 ^ { - 5 } \mathrm { eV }$
B) $2.27 \times 10 ^ { - 5 } \mathrm { eV }$
C) $2.70 \times 10 ^ { - 5 } \mathrm { eV }$
D) $7.22 \times 10 ^ { - 5 } \mathrm { eV }$