Bohr Model Calculator

Calculate energy levels and orbital radii for hydrogenic atoms using the classic Bohr model.

Inputs

Provide a principal quantum number and atomic number, then compute the energy level and radius.

How to Use This Calculator

Enter the principal quantum number and the atomic number of the nucleus you are modeling. Hit Calculate to instantly see the energy in electronvolts and the orbital radius in ångströms.

Methodology

The Bohr model treats the electron as rotating in circular orbits where angular momentum is quantized. This calculator applies the analytic expressions for a hydrogenic atom and ignores fine structure, relativity, and multi-electron corrections.

Full original guide (expanded)

Source of Data and Methodology

All calculations are based on the Bohr model of the hydrogen atom as described in standard quantum mechanics textbooks.

The Formula Explained

Energy: \( E_n = - \frac{13.6 \times Z^2}{n^2} \) eV

Radius: \( r_n = 0.529 \times \frac{n^2}{Z} \) Å

Glossary of Variables

  • n: Principal quantum number
  • Z: Atomic number
  • Energy Level: The energy of an electron at a particular orbit
  • Radius: The radius of the electron's orbit

FAQs

What is the Bohr Model?

The Bohr Model is a theory that describes the hydrogen atom with quantized electron orbits.

Why use the Bohr Model?

It simplifies understanding of atomic structures and energy levels.

What is a quantum number?

A quantum number defines the state of an electron in an atom.

Formulas

Energy level (eV):

Eₙ = -13.6 × Z² / n²

Orbital radius (Å):

rₙ = 0.529 × n² / Z

  • n: Principal quantum number (positive integer)
  • Z: Atomic number (positive integer)
  • Energy is negative for bound states; radius is in ångströms.
Citations

NIST — Weights and measures — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/weights-and-measures

FTC — Consumer advice — consumer.ftc.gov · Accessed 2026-01-19
https://consumer.ftc.gov/

Changelog

0.1.0-draft · 2026-01-19

  • Initial audit spec draft generated from HTML extraction (review required).
  • Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
  • Confirm sources are authoritative and relevant to the calculator methodology.
Verified by Ugo Candido Last Updated: 2026-01-19 Version 0.1.0-draft
Version 1.5.0