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Worksheetschem chapter 7
Total questions: 96
Worksheet time: 54mins
Quantum mechanics explains
How macroscopic objects move
The behavior of the absolutely small such as electrons
The structure of molecules only
The expansion of gases
Electrons are about how many times smaller than a hydrogen atom?
10
1 000
10 000
1 000 000
The speed of electromagnetic radiation in a vacuum is
3.00 × 10⁵ m/s
3.00 × 10⁸ m/s
3.00 × 10¹⁰ m/s
3.00 × 10⁻⁸ m/s
Wavelength (λ) is
Height of the wave
Distance between adjacent crests
Time for one oscillation
Number of cycles per second
Frequency (ν) is measured in
J mol⁻¹
Hz (or s⁻¹)
m/s
W/m²
Relationship among c, λ, and ν:
c = λ × ν
c = λ/ν
ν = λ × c
λ = c² ν
As wavelength increases, frequency
Increases
Decreases
Stays constant
Among electromagnetic waves, the lowest energy belongs to
Gamma rays
Radio waves
Ultraviolet
X-rays
Amplitude refers to
Distance between crests
Height of a crest
Speed of light
Interference occurs when
Two light waves combine to give reinforcement or cancellation
Light strikes metal and emits electrons
Diffraction is
Bending of light around obstacles
Straight-line travel of light
Planck proposed that light energy is
Continuous
Quantized in packets
The energy of one photon is given by
E = mc²
E = hν
E = hc λ
The photoelectric effect shows that light behaves as
Only a wave
Only a particle
Both a wave and a particle
The energy of a photon increases as
Wavelength increases
Frequency increases
Bohr suggested electrons travel in
Random paths
Circular orbits of fixed energy
A Bohr orbit of fixed energy is called a
Standing wave
Stationary state
When an electron jumps from higher to lower n, it
Absorbs energy
Emits a photon
The de Broglie relation is
(a)
Increasing an electron’s velocity will make its wavelength
Larger
Smaller
Wave-particle duality applies to
Light only
All matter
The Heisenberg uncertainty principle states
Complementary properties of electrons are
In quantum mechanics, electrons are represented by
Orbits
Orbitals (wave functions ψ)
ψ² represents
Energy
Probability density
The Schrödinger equation describes
Motion of planets
Behavior of electron waves in atoms
Principal quantum number (n) indicates
Orbital shape
Size and energy level
Possible n values = 1, 2, 3,… ∞
True
False
Angular momentum quantum number (l) describes
Shape of orbital
Orbital orientation
For n = 3, l can be
0, 1, 2
0, 1
1, 2, 3
l = 0 → _____ orbital
p
s
l = 1 → _____ orbital
s
p
d
Magnetic quantum number (ml) defines
Orbital orientation
Orbital shape
For l = 2, possible ml values =
–2, –1, 0, +1, +2
–1, 0, +1
0, 1, 2
The number of orbitals in a shell =
n²
2n²
l²
The maximum number of electrons in a shell =
2n²
n²
8
Spin quantum number (ms) =
+½ or –½
0 or 1
-1, 0, +1
Two electrons in one orbital must have
Opposite spins
The same spin
The s orbital shape is
Spherical
Dumbbell
Cloverleaf
The p orbitals are
Dumbbell shaped
Spherical
Complex
Number of p orbitals per energy level = 3
True
False
Hydrogen ground-state configuration: 1s¹
True
False
The Stern–Gerlach experiment proved
(a)
Electron spin quantum numbers are
+½ (spin up) and –½ (spin down)
+1 and -1
0 and 1
Pauli Exclusion Principle states
No two electrons share all four quantum numbers
Electrons fill orbitals singly first
Hund’s rule states
Degenerate orbitals fill singly with parallel spins first
Lowest energy orbitals fill first
Aufbau principle states
Lowest-energy orbitals fill first
Orbitals fill with paired electrons first
For hydrogen, 3s = 3p = 3d in energy
True
False
In multi-electron atoms, energies depend on
Both n and l
Only n
Only l
Relative energies within same n: E(s) < E(p) < E(d) < E(f)
True
False
“Penetration” explains
Why 4s is filled before 3d
The photoelectric effect
Light behaves as
A) only a wave
B) only a particle
C) both wave and particle
D) neither ✅ C
Which has the longest wavelength?
A) X-rays
B) Infrared
C) Visible
D) Radio
Planck explained blackbody radiation by assuming energy is
A) continuous
B) quantized
C) lost
D) constant
Work function (Φ) is
A) energy needed to remove electron
B) electron mass
C) Planck constant
D) threshold frequency
No electrons are ejected when
A) E < Φ
B) E = Φ
C) E > Φ
D) ν > ν₀
The line spectrum of hydrogen results from
A) ionization
B) electron transitions
C) nuclear decay
D) diffraction
When n₂ > n₁, an electron moves
A) to lower E
B) to higher E
C) no change
Electron wavelength increases when
A) velocity increases
B) mass increases
C) velocity decreases
D) h decreases
An atom with all paired electrons is A) paramagnetic B) diamagnetic C) magnetic D) unstable ✅ B
A) paramagnetic
B) diamagnetic
C)magnetic
D)unstable
Which subshell fills after 4s according to the Aufbau principle?
A) 3d
B) 4p
C) 2s
Bohr’s model explained
A) nuclear fusion
B) atomic line spectra
C) diffraction
D) nuclear decay
de Broglie proposed that
A) photons have mass
B) moving particles have wave properties
C) electrons are stationary
D) λ increases with mass
ψ² represents
A) electron energy
B) position
C) probability density
D) charge
Uncertainty principle means
A) we can know both position and momentum precisely
B) we cannot know both position and momentum precisely
C) position is always known
Electrons in the same orbital have opposite spins because of
A) Hund’s rule
B) Pauli exclusion principle
C) Aufbau principle
Orbitals are defined as
A) paths
B) 3-D regions of high probability
C) rings
Principal quantum number (n) indicates
energy level
shape
orientation
Magnetic quantum number (mₗ) ranges from
−l → +l
−n → +n
−1 → +1
0 → n
Large objects show negligible wave behavior because
none
small m
large m
Increasing temperature of a blackbody shifts radiation toward
shorter λ
longer λ
no change
lower ν
For n = 3, possible l values are
0
0,1,2,3,4
0,1,2
0,1
A paramagnetic atom or ion that contains unpaired electrons is attracted to an external magnetic field
True
False
Aufbau principle:
highest energy orbitals fill first
lowest energy orbitals fill first
half-filled only
electrons fill randomly
Pauli exclusion principle states:
Electrons must pair
Electrons fill singly first
No two electrons can share all four quantum numbers
Atoms are diamagnetic when they have
paired electrons
unpaired electrons
Orbitals with the same value of n are said to be in the same principal level (or principal shell).
True
False
The principal quantum number, n
, is an integer that determines the overall size of the orbital and indicates the energy level of an electron in an orbital
an integer that specifies the orientation of the orbital.
number is an integer that corresponds primarily with the shape of the orbital.
The angular momentum number (l)
, is an integer that determines the overall size of the orbital and indicates the energy level of an electron in an orbital
an integer that specifies the orientation of the orbital.
number is an integer that corresponds primarily with the shape of the orbital.
The magnetic quantum number, ml
, is an integer that determines the overall size of the orbital and indicates the energy level of an electron in an orbital
an integer that specifies the orientation of the orbital.
number is an integer that corresponds primarily with the shape of the orbital.
The orbitals within a principal level of a multielectron atom are degenerate; their energy depends on the value of l.
True
False
two electrons occupying the same orbital have three identical quantum numbers (n, l, and ml), they must have different spin quantum numbers. which principle is this
The Bohr Model
The Schrödinger Equation
Pauli Exclusion Principle
suggested that electrons traveled in circular orbits that could exist only at specific fixed distances from the nucleus.
The Bohr Model
The Schrödinger Equation
The Stern-Gerlach Experiment
what was was demonstrated experimentally in the Stern-Gerlach experiment
quantum number
electron spin (ms)
wave function
Sublevel energy splitting
caused by orbital penetration
lower l values= lower energy
4s 3d orbitals are far from each other
5s and 4d orbitals are similar close
4s fills before 3d in most first-row transition metals; which ones are exceptions
Cr
Cu
Fe
Br
The electron configuration of anions is
determined by adding the number of electrons indicated by the magnitude of the charge.
is determined by subtracting the number of electrons indicated by the magnitude of the charge
The electron configuration of cations is
determined by adding the number of electrons indicated by the magnitude of the charge.
is determined by subtracting the number of electrons indicated by the magnitude of the charge
Orbital with the same n value
Principal level/shell
Sublevel shell
Sublevel shell
orbital with the same n value
orbital with the same l value
orbital with the same n and l value
orbital with neither of them
A paramagnetic atom
contains paired electrons
contains unpaired electrons is
attracted to an external magnetic field
not attracted to an external magnetic field
is specified by three interrelated quantum numbers that can be found in the radial and angular components of the wave function
orbital
quantum number
work
wave
• Orbitals with the same value of n and l are said to be in the same
principal level
sublevel
orbital
Each orbital can have a maximum of only____, with opposing spins
1 electron
2 electrons
3 electrons
4 electrons
In the hydrogen atom, the energy of an orbital depends only on
n
l
ml
ms
the orbitals within multielectron atom are
degenerate
degenerate and depend on the l
degenerate and depend on the n
are not degenerate and depend on the l
