Calculate Electron Configuration
2. Pauli Exclusion Principle: Each orbital holds max 2 electrons with opposite spins.
3. Hund’s Rule: Electrons fill degenerate orbitals singly before pairing.
The order of filling is: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p
Quickly find the electron configuration of any element on the periodic table. Great for chemistry students, educators, and curious minds alike.
What is Electron Configuration?
Electron configuration describes how electrons are arranged in an atom’s electron shells and subshells. It shows which orbitals (s, p, d, f) electrons occupy — and in what order.
Understanding electron configurations is essential for:
- Predicting chemical behavior
- Understanding reactivity and bonding
- Interpreting periodic trends (like ionization energy and atomic size)
How to Determine Electron Configuration
Electron configurations are built using:
- The Aufbau principle (electrons fill lowest-energy orbitals first)
- Hund’s rule (electrons occupy orbitals singly before pairing)
- The Pauli exclusion principle (each orbital holds 2 electrons max)
General Notation:
Electron configurations are typically written as:
1s² 2s² 2p⁶ 3s² 3p⁶ ...
Each term tells you:
- Principal energy level (1, 2, 3, …)
- Subshell (s, p, d, f)
- Number of electrons in that subshell (superscript)
Using the Electron Configuration Calculator
- Enter or select an element by name, symbol, or atomic number
- Click Calculate
- Instantly get:
- Full electron configuration
- Noble gas shorthand
- Orbital diagram (optional)
- Element details (e.g., atomic number, mass, group, period)
Bonus: Some versions may also show valence electrons and block type (s, p, d, f).
Example: Oxygen (Atomic Number 8)
- Full configuration: 1s² 2s² 2p⁴
- Shorthand configuration: [He] 2s² 2p⁴
- Valence electrons: 6
- Block: p-block
This setup helps explain why oxygen forms two bonds in molecules like H₂O — it needs two more electrons to complete its octet.
Who Should Use This Calculator?
- Chemistry students solving homework
- Teachers preparing quizzes and lessons
- Competitive exam aspirants (MCAT, GRE, etc.)
- Anyone interested in learning atomic structure
FAQs
What is noble gas shorthand?
It’s a simplified way of writing electron configurations using the symbol of the nearest noble gas in brackets to represent core electrons. Example:
Na = [Ne] 3s¹
How many electrons fit in each subshell?
- s = 2
- p = 6
- d = 10
- f = 14
Does this work for ions?
Yes, for most ions — but be careful with transition metals; their electron loss doesn’t always follow the strict order.
