Electron Configuration Calculator
Calculate Electron Configuration
Enter an element’s atomic number, symbol, or element name. The tool returns full configuration and noble‑gas shorthand where possible.
Type an element and click Calculate.
How this works
The calculator fills subshells in order of increasing energy using the aufbau principle (1s → 2s → 2p → 3s → …). It also provides a condensed noble‑gas shorthand and handles common anomalous configurations (e.g., Cr, Cu, Pd) using a small exceptions table.
Electron Configuration — Explained
Electron configuration describes how electrons are distributed across the orbitals of an atom. It’s essential for predicting chemical behavior: bonding patterns, magnetism, and ionization properties. This calculator helps you get both the full configuration and the noble‑gas shorthand for any neutral atom.
Why it matters
Knowing the electron configuration lets chemists and students predict the valence electrons, oxidation states, and the element’s placement in the periodic table. For example, the configuration of iron (Fe) is [Ar] 4s2 3d6, which indicates 6 d‑electrons and 2 s‑electrons in the outer shells.
Examples
- Hydrogen (H): 1s1
- Carbon (C): 1s2 2s2 2p2
- Chromium (Cr): [Ar] 3d5 4s1 (anomalous configuration)
Common questions
- Q: What is noble‑gas shorthand?
- A: It uses the previous noble gas in brackets to replace the inner core electrons. Example: sodium is [Ne] 3s1.
- Q: Does this calculator handle ions?
- A: Currently it computes neutral atoms. If you need ionic configurations, enter the total electron count (atomic number ± charge) using the “Total electrons” box.
- Q: Why are some electron configurations “anomalous”?
- A: Certain elements gain extra stability from half‑filled or fully filled d and f subshells. The calculator accounts for the most common exceptions.
Further reading
Learn about Hund’s rule, Pauli exclusion principle, and aufbau principle to deepen your understanding of how orbitals are filled.