CHEM 103 PORTAGE LEARNING EXAM 2
(PROBLEM SET) AND EXAM
STUDYGUIDE QUESTIONS AND
ANSWERS WITH COMPLETE
SOLUTIONS LATEST UPDATED
2026/2027
Q: Which scientific theories and experiments provide evidence for the
wave-like behavior of light?
A: ✔️✔️
Huygens' Principle: Christiaan Huygens demonstrated that light
behavior during reflection and refraction could be explained by treating
light as a wavefront.
Young’s Double-Slit Experiment: Thomas Young showed that light
passing through two narrow slits creates an interference pattern (multiple
lines) on a screen, a characteristic behavior exclusive to waves.
Maxwell’s Equations: James Clerk Maxwell developed the theory of
electromagnetism, proving that light is an electromagnetic wave
traveling through space.
Q: Which findings and theories suggest that light behaves as a particle?
A: ✔️✔️
Newtonian Corpuscular Theory: Isaac Newton proposed that light
consists of "corpuscles" (tiny particles) that follow standard laws of
motion and travel at immense speeds.
The Photoelectric Effect: This phenomenon demonstrates that light can
eject electrons from a metal surface, behaving as discrete packets of
energy (photons) rather than a continuous wave.
Blackbody Radiation: Observations of how objects emit thermal
radiation showed that energy is quantized, which contradicts classical
wave theory and supports the particle model.
What is the wavelength of microwave radiation with a frequency of 450 MHz?
Equation:
Equation with values substituted:
, Answer (with correct units and to 3 significant figures):
λ = C/V
450 MHz -> Hz = 450 x 1 x 10 ^6Hz = 4.5 x 10^8
λ = 2.998 x 10^8m/s / 4.5 x 10^8
λ=0.6662
What is the energy of a photon being emitted by a radio wave that has a
wavelength of 180 m?
Equation:
Equation with values substituted:
Answer (with correct units and to 3 significant figures):
E = hc/λ
E = (6.626 x 10^-34js)(2.998 x 10^8m/s) / 180m
E = 1.10 x 10^-26j
What are the main features from Bohr's model of the hydrogen atom that apply
to all models used to describe the distribution of electrons in an atom?
- The energies of electrons (energy levels) in an atom are quantized.
- An electron's energy increases with increasing distance from the nucleus.
- The discrete energies of light emitted by elements in an excited state result
from quantized electronic energies.
A source of energy promotes an electron in a hydrogen atom from ground state
into an orbit with n = 8. What is the calculated energy (in Joules) of the
electron in this excited state?
Equation:
Equation with values substituted:
Answer (with correct units and to 3 significant figures):
En=-K/n2
En= - (2.179 x 10-18J)/82
En= -3.40 x 10-20J
An electron in a hydrogen atom transitions from an orbit with n = 4 to the orbit
with n = 7.
What is the calculated energy absorbed by the electron?
A.) En=-K/n2
(PROBLEM SET) AND EXAM
STUDYGUIDE QUESTIONS AND
ANSWERS WITH COMPLETE
SOLUTIONS LATEST UPDATED
2026/2027
Q: Which scientific theories and experiments provide evidence for the
wave-like behavior of light?
A: ✔️✔️
Huygens' Principle: Christiaan Huygens demonstrated that light
behavior during reflection and refraction could be explained by treating
light as a wavefront.
Young’s Double-Slit Experiment: Thomas Young showed that light
passing through two narrow slits creates an interference pattern (multiple
lines) on a screen, a characteristic behavior exclusive to waves.
Maxwell’s Equations: James Clerk Maxwell developed the theory of
electromagnetism, proving that light is an electromagnetic wave
traveling through space.
Q: Which findings and theories suggest that light behaves as a particle?
A: ✔️✔️
Newtonian Corpuscular Theory: Isaac Newton proposed that light
consists of "corpuscles" (tiny particles) that follow standard laws of
motion and travel at immense speeds.
The Photoelectric Effect: This phenomenon demonstrates that light can
eject electrons from a metal surface, behaving as discrete packets of
energy (photons) rather than a continuous wave.
Blackbody Radiation: Observations of how objects emit thermal
radiation showed that energy is quantized, which contradicts classical
wave theory and supports the particle model.
What is the wavelength of microwave radiation with a frequency of 450 MHz?
Equation:
Equation with values substituted:
, Answer (with correct units and to 3 significant figures):
λ = C/V
450 MHz -> Hz = 450 x 1 x 10 ^6Hz = 4.5 x 10^8
λ = 2.998 x 10^8m/s / 4.5 x 10^8
λ=0.6662
What is the energy of a photon being emitted by a radio wave that has a
wavelength of 180 m?
Equation:
Equation with values substituted:
Answer (with correct units and to 3 significant figures):
E = hc/λ
E = (6.626 x 10^-34js)(2.998 x 10^8m/s) / 180m
E = 1.10 x 10^-26j
What are the main features from Bohr's model of the hydrogen atom that apply
to all models used to describe the distribution of electrons in an atom?
- The energies of electrons (energy levels) in an atom are quantized.
- An electron's energy increases with increasing distance from the nucleus.
- The discrete energies of light emitted by elements in an excited state result
from quantized electronic energies.
A source of energy promotes an electron in a hydrogen atom from ground state
into an orbit with n = 8. What is the calculated energy (in Joules) of the
electron in this excited state?
Equation:
Equation with values substituted:
Answer (with correct units and to 3 significant figures):
En=-K/n2
En= - (2.179 x 10-18J)/82
En= -3.40 x 10-20J
An electron in a hydrogen atom transitions from an orbit with n = 4 to the orbit
with n = 7.
What is the calculated energy absorbed by the electron?
A.) En=-K/n2
