Home Wikituition Browse all terms Categories
Random term

Quantum & Atomic Physics

60 terms · page 1 of 3


A–Z
All A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Filtering by: Quantum & Atomic Physics Clear all
Quantum & Atomic Physics

Atomic Orbital

A mathematical function describing the three-dimensional spatial wave function and probability distribution of an electron in an atom.

ψ_n,l,m_l(r, θ, φ) = R_n,l(r) Y_l,m_l(θ, φ) Dimensionless Spatial Function
Quantum & Atomic Physics

Aufbau Principle

A rule governing electron configuration stating that electrons fill atomic orbitals of lower energy levels before occupying higher energy…

Order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s... Dimensionless Rule
Quantum & Atomic Physics

Auger Effect

A non-radiative atomic process in which the filling of an inner-shell electron vacancy causes the ejection of a second outer-shell (Auger)…

E_Auger = E_K - E_L1 - E_L2,3 eV (Electron-Volts)
Quantum & Atomic Physics

Balmer Series

The spectral series of hydrogen atom emission lines resulting from electron transitions dropping from higher levels (n_i ≥ 3) to the n=2…

1 / λ = R_H (1 / 2² - 1 / n_i²), n_i = 3, 4, 5... Visible Light Wavelengths (nm)
Quantum & Atomic Physics

Bell's Theorem

A mathematical theorem proving that no physical theory incorporating local hidden variables can reproduce all predictions of quantum…

|E(a, b) - E(a, b')| + |E(a', b) + E(a', b')| ≤ 2 Dimensionless Inequality
Quantum & Atomic Physics

Bohr Model

An early semi-classical atomic model proposing that electrons orbit the atomic nucleus only in discrete stationary orbits with quantized…

L = m v r = n ℏ, E_n = -13.6 eV / n² eV (Energy), m (Orbit Radius)
Quantum & Atomic Physics

Bose-Einstein Condensate (BEC)

A state of matter formed by bosons cooled close to absolute zero, where a macroscopic fraction of particles collapse into the lowest…

T_c = (2 π ℏ² / (m k_B)) (n / ζ(3/2))^(2/3) nK (Nanokelvin Temperatures)
Quantum & Atomic Physics

Bosons

Subatomic particles possessing integer intrinsic spin that obey Bose-Einstein statistics and do not obey the Pauli Exclusion Principle.

Spin = 0, 1, 2... Dimensionless Particle Class
Quantum & Atomic Physics

Bragg's Law

The mathematical condition for constructive interference of waves scattered from parallel atomic lattice planes in a crystal.

n λ = 2 d sin θ m or nm (Wavelength and Spacing)
Quantum & Atomic Physics

Casimir Effect

An attractive physical force acting between two uncharged parallel conductive plates in vacuum, arising from quantum vacuum fluctuations.

F / A = - (π² ℏ c) / (240 d⁴) N/m² (Pressure)
Quantum & Atomic Physics

Commutator

A mathematical operator evaluating whether two quantum mechanical operators commute with one another.

[Â, B̂] =  B̂ - B̂  Product Unit of  and B̂
Quantum & Atomic Physics

Compton Effect

The decrease in energy (increase in wavelength) of an X-ray or gamma-ray photon when scattered by a stationary electron.

Δλ = λ' - λ = (h / (m_e c)) (1 - cos θ) m or pm (Wavelength Increase)
Quantum & Atomic Physics

Davisson-Germer Experiment

A 1927 physics experiment that experimentally confirmed De Broglie's matter wave hypothesis by demonstrating electron diffraction from a…

n λ = 2 d sin θ = h / p nm (Wavelength)
Quantum & Atomic Physics

De Broglie Wavelength

The wavelength associated with a massive particle, expressing its intrinsic wave-like character.

λ = h / p = h / (m v) m or nm (Wavelength)
Quantum & Atomic Physics

Electron Spin

An intrinsic form of angular momentum carried by elementary particles, independent of orbital spatial motion.

S = √(s (s + 1)) ℏ, s = ½, S_z = ± ½ ℏ J·s (Spin Angular Momentum)
Quantum & Atomic Physics

Expectation Value

The probabilistic average or expected value of many physical measurements performed on an ensemble of identically prepared quantum states.

⟨A⟩ = ∫ ψ* Â ψ dx / ∫ ψ* ψ dx Same as measured quantity
Quantum & Atomic Physics

Fermi Energy

The highest occupied kinetic energy state of non-interacting fermions in a quantum system at absolute zero temperature (0 K).

E_F = (ℏ² / (2 m)) (3 π² n)^(2/3) eV or Joules
Quantum & Atomic Physics

Fermions

Subatomic particles possessing half-integer intrinsic spin that obey Fermi-Dirac statistics and the Pauli Exclusion Principle.

Spin = ½, ³/₂, ⁵/₂... Dimensionless Particle Class
Quantum & Atomic Physics

Fine Structure

The small splitting of atomic spectral lines resulting from relativistic mass corrections and spin-orbit coupling.

E_fine ~ α² E_n, α ≈ 1 / 137 eV (Energy Splitting)
Quantum & Atomic Physics

Finite Potential Well

A quantum potential well model with barriers of finite energy height V₀.

V(x) = V₀ for |x| > a, V(x) = 0 for |x| ≤ a eV or Joules
Quantum & Atomic Physics

Fluorescence

The rapid absorption of light at a shorter wavelength followed by immediate emission of light at a longer wavelength.

h ν_emitted < h ν_absorbed (Stokes Shift) Nanoseconds (Lifetime)
Quantum & Atomic Physics

Franck-Hertz Experiment

An influential 1914 physics experiment that directly demonstrated the existence of quantized discrete energy states in mercury atoms.

E_loss = h ν = 4.9 eV (for Mercury vapor) eV (Electron-Volts)
Quantum & Atomic Physics

Heisenberg Uncertainty Principle

A fundamental quantum limit stating that canonical conjugate physical variables (such as position and momentum, or energy and time) cannot…

Δx Δp ≥ ℏ / 2, ΔE Δt ≥ ℏ / 2 J·s (Action Units)
Quantum & Atomic Physics

Hund's Rule of Maximum Multiplicity

A rule stating that when filling degenerate atomic orbitals, electrons occupy separate orbitals singly with parallel spins before pairing…

S_total = ∑ s_i (Maximized spin in degenerate orbitals) Dimensionless Rule