CEM 141 MSU Exam 2
QUESTIONS WITH ANSWERS 2025/2026
Lights acts as what? - ✔✔Particle and wave.
Wavelength - ✔✔The distance (m) of waves from peak to peak. Short: x-
ray (red), long: infrared (blue)
Short - higher energy
Long - lower energy
Frequency (V) - ✔✔The number of wavefronts per second. Highest: x-
ray
Velocity of Light - ✔✔C = 3.00 X 10^8
= wavelength X frequency
Amplitude - ✔✔The intensity, height of peaks of waves. Highest: blue
light
,Energy of Wave (J) - ✔✔Increases as frequency increases and as
wavelength decreases. Highest: x-ray
Range of Wavelengths - ✔✔10^-16 - 10^8 = 24. Only a third are visible
Black Body Radiation - ✔✔When a mass is heated it emits a type of EM
radiation, at very high temps the mass becomes "white hot" because all
wavelengths of visible light become equally intense
Photoelectric Effect - ✔✔Metals emit electrons when electromagnetic
radiation shines on the surface, light is transfers energy to the electrons
at the metal's surface where it's transformed into KE that gives the
electrons enough energy to leave the atom
Depends on frequency not intensity
How many electrons are emitted if the light is below it's threshold
frequency no matter the intensity? - ✔✔None.
What increases the number of electrons to be emitted by the
photoelectric effect? - ✔✔Intensity.
A particle that transfers light energy with a definable energy, emits one
electron
, energy of = h (6.626 x 10^-34 J) - ✔✔Photon.
Energy of light equation? - ✔✔E = hV.
h - ✔✔Planck's constant, the energy of a photon.
What happens to the energy when there is a short wavelength? -
✔✔High energy.
Light from the sun (white light) can be separated by a prism to create
this, only a small part of the full EM spectrum? - ✔✔Visible Spectrum.
Atomic Emission Spectrum - ✔✔Spectrum that emits photons, energy
diagram: electron goes down energy levels.
Atomic Absorption Spectrum - ✔✔Spectrum that absorbs photons,
energy diagram: electrons goes up in energy levels.
Heisenberg Uncertainty Principle - ✔✔Principle states that we can't
accurately measure both the position and the energy of a small particle
(electron)
Bohr's model did - why its wrong.
QUESTIONS WITH ANSWERS 2025/2026
Lights acts as what? - ✔✔Particle and wave.
Wavelength - ✔✔The distance (m) of waves from peak to peak. Short: x-
ray (red), long: infrared (blue)
Short - higher energy
Long - lower energy
Frequency (V) - ✔✔The number of wavefronts per second. Highest: x-
ray
Velocity of Light - ✔✔C = 3.00 X 10^8
= wavelength X frequency
Amplitude - ✔✔The intensity, height of peaks of waves. Highest: blue
light
,Energy of Wave (J) - ✔✔Increases as frequency increases and as
wavelength decreases. Highest: x-ray
Range of Wavelengths - ✔✔10^-16 - 10^8 = 24. Only a third are visible
Black Body Radiation - ✔✔When a mass is heated it emits a type of EM
radiation, at very high temps the mass becomes "white hot" because all
wavelengths of visible light become equally intense
Photoelectric Effect - ✔✔Metals emit electrons when electromagnetic
radiation shines on the surface, light is transfers energy to the electrons
at the metal's surface where it's transformed into KE that gives the
electrons enough energy to leave the atom
Depends on frequency not intensity
How many electrons are emitted if the light is below it's threshold
frequency no matter the intensity? - ✔✔None.
What increases the number of electrons to be emitted by the
photoelectric effect? - ✔✔Intensity.
A particle that transfers light energy with a definable energy, emits one
electron
, energy of = h (6.626 x 10^-34 J) - ✔✔Photon.
Energy of light equation? - ✔✔E = hV.
h - ✔✔Planck's constant, the energy of a photon.
What happens to the energy when there is a short wavelength? -
✔✔High energy.
Light from the sun (white light) can be separated by a prism to create
this, only a small part of the full EM spectrum? - ✔✔Visible Spectrum.
Atomic Emission Spectrum - ✔✔Spectrum that emits photons, energy
diagram: electron goes down energy levels.
Atomic Absorption Spectrum - ✔✔Spectrum that absorbs photons,
energy diagram: electrons goes up in energy levels.
Heisenberg Uncertainty Principle - ✔✔Principle states that we can't
accurately measure both the position and the energy of a small particle
(electron)
Bohr's model did - why its wrong.
