Learning
These are original practice questions written for study. They are not official
CHEM 103, Portage Learning, or university exam questions and are not copied
from any copyrighted question bank. They cover common CHEM 103 Module 7
topics: quantum theory, electromagnetic radiation, Bohr model, quantum
numbers, orbitals, and electron configuration.
Question 1:
Which type of electromagnetic radiation has the shortest wavelength?
A. Radio waves
B. Microwaves
C. Visible light
D. Gamma rays
Correct answer: D
Rationale: Gamma rays have the shortest wavelengths and highest energies in
the electromagnetic spectrum.
Question 2:
Which type of electromagnetic radiation has the lowest frequency?
A. Radio waves
B. Infrared
C. Ultraviolet
D. X-rays
Correct answer: A
Rationale: Radio waves have the lowest frequencies and longest wavelengths.
Question 3:
The speed of light in a vacuum is approximately:
A. 3.00 × 10^5 m/s
B. 3.00 × 10^8 m/s
C. 3.00 × 10^10 m/s D. 3.00 × 10^12 m/s
,Correct answer: B
Rationale: The speed of light is 3.00 × 10^8 m/s.
Question 4:
Which equation relates the speed of light, wavelength, and
frequency? A. c = λν
B. c = λ/ν
C. c = ν/λ
D. c = λ + ν
Correct answer: A
Rationale: c = λν, where λ is wavelength and ν is frequency.
Question 5:
If wavelength increases, frequency:
A. Increases
B. Decreases
C. Stays the same
D. Becomes zero
Correct answer: B
Rationale: Wavelength and frequency are inversely proportional.
Question 6:
Which color of visible light has the longest wavelength?
A. Violet
B. Blue
C. Green
D. Red
Correct answer: D
Rationale: Red light has the longest wavelength in the visible spectrum.
Question 7:
Which color of visible light has the highest energy?
,A. Red
B. Orange
C. Yellow
D. Violet
Correct answer: D
Rationale: Violet light has the shortest wavelength and highest energy.
Question 8:
The energy of a photon is directly proportional to its:
A. Wavelength
B. Frequency
C. Speed
D. Mass
Correct answer: B
Rationale: E = hν, so energy is proportional to frequency.
Question 9:
Which equation gives the energy of a photon?
A. E = mc^2
B. E = hν
C. E = λν
D. E = h/λ
Correct answer: B
Rationale: Photon energy is E = hν, where h is Planck’s constant.
Question 10:
Planck’s constant is approximately:
A. 6.626 × 10^−34 J·s
B. 3.00 × 10^8 m/s
C. 1.097 × 10^7 m^−1
D. 9.11 × 10^−31 kg
Correct answer: A
, Rationale: h = 6.626 × 10^−34 J·s.
Question 11:
The photoelectric effect provides evidence that light:
A. Is only a wave
B. Has particle properties
C. Has no energy
D. Cannot eject electrons
Correct answer: B
Rationale: The photoelectric effect shows light behaves as particles called
photons.
Question 12:
In the photoelectric effect, electrons are ejected when:
A. Light frequency is below a threshold
B. Light frequency is above a threshold
C. Light intensity is zero
D. Wavelength is very long
Correct answer: B
Rationale: A minimum threshold frequency is required to eject electrons.
Question 13:
Increasing the intensity of light above the threshold frequency increases:
A. The kinetic energy of ejected electrons
B. The number of ejected electrons
C. The threshold frequency
D. The wavelength
Correct answer: B
Rationale: Intensity increases the number of photons, so more electrons are
ejected.
Question 14: