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Boltzmann Factor Ratio Calculator

Calculate relative probability of two states.

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Ratio N2/N1

Formula first

Overview

The Boltzmann factor ratio determines the relative occupancy of two energy states in a system at thermal equilibrium. It expresses how the population of a higher energy level decreases exponentially as the energy gap increases relative to the available thermal energy ( T).

Symbols

Variables

E = Energy Diff (E2-E1), T = Temperature, R = Ratio N2/N1

Energy Diff (E2-E1)
eV
Temperature
Ratio N2/N1
Variable

Apply it well

When To Use

When to use: Use this formula when analyzing the distribution of particles across discrete energy levels in systems like atomic transitions or molecular vibrations. It is applicable when the system is in thermal equilibrium and follows Maxwell-Boltzmann statistics, assuming non-interacting particles.

Why it matters: This relationship is the foundation of statistical thermodynamics, explaining why chemical reactions accelerate with temperature and how spectral lines are formed. It allows scientists to predict the behavior of matter from microscopic quantum states to macroscopic heat transfer.

Avoid these traps

Common Mistakes

  • Forgetting negative sign.
  • Using E instead of Δ E.

One free problem

Practice Problem

Calculate the ratio of atoms in an excited state relative to the ground state if the energy difference is 1.0 ×10⁻²⁰ J and the system is at 300 K.

Energy Diff (E2-E1)1e-20 eV
Temperature300 K

Solve for:

Hint: The ratio R is equal to e raised to the power of (-dE / (kB ×T)).

The full worked solution stays in the interactive walkthrough.

References

Sources

  1. Atkins' Physical Chemistry
  2. Callen, H. B. (1985). Thermodynamics and an Introduction to Thermostatistics.
  3. Wikipedia: Boltzmann distribution
  4. NIST CODATA 2018
  5. Atkins' Physical Chemistry, 11th Edition
  6. Callen, H. B. (1985). Thermodynamics and an Introduction to Thermostatistics, 2nd Edition
  7. McQuarrie, D. A. (2000). Statistical Mechanics, 2nd Edition
  8. Statistical Mechanics by Donald A. McQuarrie