Quantum Mechanics Flashcards

Flashcards covering key vocabulary terms related to Quantum Mechanics.

Quantum Mechanics

Uses math to describe atomic behavior and electron positions.

Newton's Mechanics

Laws of motion described by Newton.

Light

Electromagnetic wave that travels through a vacuum.

Wavelength (λ)

Distance between peaks of a wave.

Frequency (v)

Waves per second (Hz = 1/s).

Wavenumber (v)

Waves per unit distance (cm-1).

Gamma Rays

Shortest λ, highest energy, dangerous.

UV Radiation

Damages living tissue.

Visible Light

0.4-0.7 μm, detected by human eyes.

Thermal Radiation

Heat emitted by objects.

Radio/TV Waves

Long λ, low energy (cm-m).

Black-body Radiation

Electromagnetic radiation emitted by hot objects.

Perfect Black Body

Hypothetical object that absorbs all electromagnetic radiation that falls on it

Rayleigh-Jeans Law

Treated electromagnetic field as many oscillators with all frequencies.

UV Catastrophe

Predicts infinite energy at short wavelengths (high frequencies)

Planck Distribution

Energy is quantized, E=nhv.

Planck's Constant (h)

h = 6.626 × 10-34 Js

Heat Capacities

Monatomic solids have molar heat capacities < 3R at low temperatures.

Einstein Model

Atoms oscillate at a fixed frequency (v); Energy is quantized: E = nhv

Debye Model

Accounts for full frequency spectrum.

Spectroscopy

Analyzes electromagnetic radiation absorbed, emitted, or scattered by a substance.

Spectrum

Record of light intensity as a function of frequency (v), wavelength (λ), or wavenumber (v = v/c).

Bohr Condition

Radiation is absorbed/emitted at discrete frequencies only; ΔE = hv

Photons

Energy packets of electromagnetic radiation; E = hv

Photoelectric Effect

Ejection of electrons from metals when exposed to ultraviolet radiation.

Work Function (Φ)

Minimum energy needed to remove an electron from metal.

Davisson and Germer

Observed electron diffraction by a crystal, proving electrons behave as waves.

Diffraction

Interference caused by an object in the wave path.

de Broglie Hypothesis

Particles have a wavelength: λ = h/p

Heisenberg Uncertainty Principle

It is impossible to know both the position and momentum of a particle exactly at the same time.

Wavefunction (Ψ)

Describes all dynamic properties of a system; Probability of finding a particle near a point is proportional to |Ψ|^2.

Normalization

Ensures the total probability of finding a particle in all space equals 1.

Schrödinger Equation

Solutions give quantized energy levels; HΨ = EΨ

Hamiltonian operator

Operator

Eigenvalue

Energy

Eigenfunction

Function