Quantum Chemistry Intro Notes
LIGHT!
The wave nature of light
 Important vocabulary:
o Wavelength (λ)—
o
Frequency (v)—
o
Speed (c)—
o
Energy (E)—
Relationships:
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Wavelength/frequency:

Frequency/energy
Visible light spectrum: ROY G. BV
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Which has the shortest wavelength?
Longest wavelength?
Lowest frequency?
Highest frequency?
Lowest energy?
Highest energy?
There are more waves than just light waves…
All travel at the _________ ________________ but have different wavelengths, frequencies, and energies.
So light is just a wave. Well…maybe not.
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Considering light as a wave explains some of its behavior, but doesn’t describe light’s interactions with _______
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Heated objected only __________ certain _______________ of light at a given ________________.
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Some ____________ ______________ electrons when light of a specific frequency shines on them.
The particle nature of light
The Quantum Concept
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____________________ is a measure of kinetic energy of particles.
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Why does iron first glow red, then orange, then blue when heated? Wave model ______________ explain this!
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Matter can __________________________________________ only in small, specific amounts called quanta.
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A quantum is the __________________________________________ that can be gained or lost by an atom.
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A quantum is very small, so it appears that energy can be absorbed and emitted ______________________.
A relationship exists between the energy of a quantum and the frequency of the emitted radiation.
The photoelectric effect
Electrons, ________________ _____________________, are emitted from a metal’s surface when light of a certain
frequency or higher, shines on a surface.
So light is a particle…and a wave….
Yes! Einstein came up with a theory:
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Light has ______________like AND _________________________like properties.
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Light can be thought of as a beam of bundles of energy called photons.
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Photons are _______________ particles that carry quanta of energy.
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The _____________ of a photon depends on its ___________________.