What this calculator does
Hydrogen-Like Atom works out electron energy level and orbital radius in a one-electron atom or ion, from the Bohr model. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
FormulaEn = −13.605693 eV × Z²/n²; rn = n²/Z × a0, a0 = 0.0529177 nm
The inputs explained
| Field | What to enter |
|---|---|
| Atomic number (Z) | A number. Starts at 1. |
| Principal quantum number (n) | A number. Starts at 1. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with atomic number (z)
Every other input is held at the calculator’s starting values while atomic number (z) varies. Select any row to load that scenario into the calculator.