Free Practice Quiz Question List

05 Quantum Mechanics and Atomic Orbitals Online Quiz Questions

Use this free practice quiz with 20 questions to review 05 Quantum Mechanics and Atomic Orbitals, test your knowledge, and prepare for your next test or exam.

20 questions

Choose one

1 point

Three photons have wavelengths of $410\,\text{nm}$ , $560\,\text{nm}$ , and $720\,\text{nm}$ . Which photon has the greatest energy?

A
A photon with the shortest wavelength
B
A photon with the longest wavelength
C
A photon with the intermediate wavelength
D
All three photons have the same energy

Choose one

1 point

An electron absorbs a photon and moves from an allowed state with energy $4.0\times10^{-19}\,\text{J}$ to one with energy $1.1\times10^{-18}\,\text{J}$ . What is the energy of the absorbed photon?

A
$4.0\times10^{-19}\,\text{J}$
B
$1.1\times10^{-18}\,\text{J}$
C
$7.0\times10^{-19}\,\text{J}$
D
$1.5\times10^{-18}\,\text{J}$

Choose one

1 point

A particle’s momentum increases to three times its original value while Planck’s constant remains unchanged. According to the de Broglie relation, how does its wavelength change?

A
Three times the original wavelength
B
One-third the original wavelength
C
The same wavelength
D
One-ninth the original wavelength

Choose one

1 point

A diagram shows a surface enclosing a chosen fraction of an orbital’s electron probability. What conclusion about the region outside that surface is justified?

A
The electron is confined inside a solid boundary.
B
The electron must be found on the drawn surface.
C
The probability of finding the electron outside the surface is zero.
D
The surface encloses a chosen fraction of the probability; some probability may lie outside it.

Choose one

1 point

An electron in the $n=4$ shell has angular-momentum quantum number $l=3$ . Which subshell label describes its orbital?

A
An $s$ subshell
B
A $p$ subshell
C
An $f$ subshell
D
A $d$ subshell

Choose one

1 point

For a subshell with $l=2$ , how many distinct values of $m_l$ —and therefore how many orbitals—are allowed?

A
Five
B
Three
C
Four
D
Seven

Choose one

1 point

Which proposed set of quantum numbers is allowed for an electron?

A
$n=3,\ l=2,\ m_l=+2,\ m_s=-\frac{1}{2}$
B
$n=3,\ l=3,\ m_l=0,\ m_s=+\frac{1}{2}$
C
$n=2,\ l=1,\ m_l=+2,\ m_s=-\frac{1}{2}$
D
$n=1,\ l=0,\ m_l=0,\ m_s=+1$

Choose one

1 point

Which description best identifies the characteristic shape and angular node of a $p$ orbital?

A
A spherical distribution with no angular node
B
Two lobes separated by a nodal plane through the nucleus
C
Four lobes separated by two nodal planes
D
A fixed circular path around the nucleus

Choose one

1 point

For an orbital with $n=4$ and $l=2$ , how many angular, radial, and total nodes does it have, respectively?

A
One angular node, two radial nodes, and three total nodes
B
Two angular nodes, two radial nodes, and four total nodes
C
Two angular nodes, one radial node, and three total nodes
D
One angular node, one radial node, and two total nodes

Choose one

1 point

For the same one-electron species, compare orbitals with $n=2$ and $n=4$ . Which statement correctly describes the $n=4$ orbital relative to the $n=2$ orbital?

A
The $n=4$ orbital is lower in energy and smaller on average.
B
The $n=4$ orbital is higher in energy but smaller on average.
C
The two orbitals have equal energy and equal average size.
D
The $n=4$ orbital is higher in energy and larger on average.

Choose one

1 point

An orbital is already occupied by one electron. Which statement correctly describes its remaining electron capacity and the spin relationship if a second electron occupies it?

A
It can hold two electrons only if both have the same spin.
B
It can hold at most two electrons, with opposite spins when both are present.
C
It can hold at most one electron because an orbital has one orientation.
D
It can hold three electrons if their energies are equal.

Choose one

1 point

A student compares the $2s$ and $2p$ orbitals first in hydrogen and then in a multi-electron atom. Which statement best captures the energy relationship described by the quantum-mechanical model?

A
They must have different energies in both species because their shapes differ.
B
They have equal energies in both species because their principal quantum numbers match.
C
They have equal energies in the one-electron species, but are generally not equal in a multi-electron atom.
D
They have different energies in the one-electron species, but equal energies in a multi-electron atom.

Choose one

1 point

Photon A has wavelength $2\lambda$ , while photon B has wavelength $\lambda$ . According to $E=\frac{hc}{\lambda}$ , how does the energy of photon A compare with that of photon B?

A
Photon A has twice the energy of photon B.
B
Photon A has half the energy of photon B.
C
The photons have equal energy because both travel at the speed of light.
D
Photon A has four times the energy of photon B.

Choose one

1 point

A particle’s momentum increases from $p$ to $3p$ , with Planck’s constant unchanged. How does its de Broglie wavelength change?

A
The wavelength becomes three times as large.
B
The wavelength stays the same.
C
The wavelength becomes one-third as large.
D
The wavelength becomes one-ninth as large.

Choose one

1 point

An electron has $l=2$ . Which description correctly combines the subshell identity, its number of orbitals, and the general pattern of its orbital shapes?

A
It is a p subshell with three orbitals, all of which have two lobes.
B
It is a d subshell with four orbitals, each of which has four lobes.
C
It is a d subshell with five orbitals; d orbitals generally have four lobes, with one having a different shape.
D
It is an f subshell with seven orbitals, each of which is spherical.

Choose one

1 point

For an orbital with $n=5$ and $l=2$ , how many angular nodes, radial nodes, and total nodes does it have, respectively?

A
2 angular, 1 radial, 3 total
B
2 angular, 2 radial, 4 total
C
3 angular, 1 radial, 4 total
D
2 angular, 3 radial, 5 total

Choose one

1 point

In the same one-electron species, compare orbitals with principal quantum numbers $n=2$ and $n=4$ . What is the ratio $\frac{|E_2|}{|E_4|}$ of their energy magnitudes?

A
$4$
B
$2$
C
$\frac{1}{4}$
D
$\frac{1}{2}$

Choose one

1 point

Using the allowed values of $l$ for the shell $n=4$ , the $2l+1$ orbitals in each subshell, and the two-electron limit per orbital, what is the maximum number of electrons in that shell?

A
$16$ electrons
B
$24$ electrons
C
$32$ electrons
D
$64$ electrons

Choose one

1 point

In a multi-electron atom, what conclusion is supported about a $3s$ orbital and a $3p$ orbital, and about which one is lower in energy?

A
They must be equal in energy because their principal quantum numbers match.
B
They generally need not be equal in energy, but the information given does not establish a universal ordering for the pair.
C
The $3p$ orbital must always be lower in energy because $l$ is larger.
D
They must be equal in energy because each subshell has the same number of electrons.

Choose one

1 point

In a two-slit experiment, electrons arrive at a detector as separate localized hits. After many electrons are detected, their overall distribution forms an interference pattern. Which conclusion best accounts for both observations?

A
Each electron is a classical particle, and the interference pattern must be caused only by interactions among electrons after detection.
B
Electrons behave exclusively as waves; the localized detector hits do not provide evidence about their behavior.
C
Electrons are detected as localized particles, while their accumulated distribution can show wave-like interference.
D
The experiment shows that electrons have no consistent physical properties until they reach the detector.