Boltzmann Factor Calculator

Calculate relative probabilities of energy states in thermal equilibrium using statistical mechanics

Calculate Boltzmann Factor

Energy of the first quantum state

Energy of the second quantum state

Absolute temperature of the system

Boltzmann Factor Results

0.000e+0
Boltzmann Factor (P₁/P₂)
0.000
|ΔE| / (k_B T)
0.00 K
Temperature (Kelvin)

Formula: P₁/P₂ = exp((E₂ - E₁) / (k_B × T))

Energy difference: ΔE = 0.000 eV

k_B × T: 0.000 meV

Example: Electronic States in Atoms

Energy State 1: 0.1 eV

Energy State 2: 0.2 eV

Temperature: 273.15 K (0°C)

Energy difference: 0.1 eV

Boltzmann factor: ≈ 70

Result: Lower energy state is 70× more probable

Temperature Examples

Absolute Zero

0 K

Theoretical minimum temperature

Liquid Helium

4.2 K

Superfluid helium

Liquid Nitrogen

77 K

Cryogenic applications

Room Temperature

298 K

Standard conditions

Human Body

310 K

Physiological temperature

Water Boiling

373 K

Phase transition

Physical Constants

Boltzmann Constant

k_B = 1.381 × 10⁻²³ J/K

Fundamental constant relating energy and temperature

Electron Volt

1 eV = 1.602 × 10⁻¹⁹ J

Common energy unit in atomic physics

Thermal Energy (300K)

k_B T ≈ 25.9 meV

Characteristic energy scale at room temperature

Understanding the Boltzmann Factor

What is the Boltzmann Factor?

The Boltzmann factor describes the relative probability of finding a system in different energy states at thermal equilibrium. It's fundamental to statistical mechanics and thermodynamics, determining how particles distribute among available energy levels.

Physical Significance

  • Lower energy states are more probable at low temperatures
  • Higher temperatures lead to more uniform state distribution
  • Exponential dependence on energy difference
  • Foundation for partition functions and thermodynamic properties

Mathematical Foundation

P₁/P₂ = exp((E₂ - E₁) / (k_B × T))

P ∝ exp(-E / (k_B × T))

  • P₁, P₂: Probabilities of states 1 and 2
  • E₁, E₂: Energies of the states
  • k_B: Boltzmann constant (1.381 × 10⁻²³ J/K)
  • T: Absolute temperature (Kelvin)

Key Insight: The factor depends only on the energy difference ΔE = E₂ - E₁

Applications in Physics

Atomic Physics

Electronic state populations, emission and absorption spectra, laser operation

Condensed Matter

Fermi-Dirac and Bose-Einstein distributions, phase transitions, magnetic systems

Chemical Physics

Reaction rates, equilibrium constants, molecular vibrations and rotations