Electron Configuration & Aufbau Subshell Calculator

The Aufbau principle dictates that electrons fill lower-energy atomic subshells (s, p, d, f) before occupying higher-energy orbitals.

To use the Electron Configuration & Aufbau Subshell Calculator, enter your Atomic Number (Z). The calculator instantly computes Full Electron Configuration (spdf), Abbreviated Noble Gas Notation and more. Results update in real time as you change any input — no submit button needed.

How to Use This Calculator

Enter your Atomic Number (Z) (e.g. 26 in protons). Results update instantly as you type — adjust any value to compare scenarios.

The Formula

Aufbau Principle Subshell Filling Order:

1s → 2s → 2p → 3s → 3p → 4s → 3d → 4p → 5s → 4d → 5p → 6s → 4f → 5d → 6p → 7s → 5f → 6d → 7p

Worked Example

Iron:

Full Configuration = 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁶ 4s²

Abbreviated Notation = [Ar] 3d⁶ 4s² (8 valence electrons).

Understanding Your Result

Industry average CTR benchmarks: Google Search ads average 2–5%; Display ads 0.1–0.3%. Organic search position 1 averages 27–35% CTR; position 10 averages 1–2%. Email CTR benchmarks: industry average 2–5%, excellent 5%+. For social media, LinkedIn average post CTR is 0.2–0.5%, Facebook 0.5–1.0%. CTR below benchmark typically indicates weak headlines, poor audience targeting, or ad fatigue — A/B test subject lines or headlines before adjusting bids.