Chemistry
Electron Configuration Calculator
Build the ground-state electron configuration of a neutral atom using the Aufbau order, the Pauli principle and Hund's rule.
Your inputs
Change any value to update the result instantly.
Ground-state configuration
1s2 2s2 2p6 3s2 3p6 4s2 3d6
Total electrons
26
Highest occupied shell
4
Electrons in the outermost shell
2
Aufbau prediction
1s2 2s2 2p6 3s2 3p6 4s2 3d6
Configuration predicted by the Aufbau order. A handful of transition and inner-transition elements deviate experimentally.
What this calculator does
Generates the ground-state electron configuration of a neutral atom using the Aufbau filling order with the Pauli exclusion principle and Hund's rule.
What your result means
The configuration lists each subshell with its electron count, in filling order, together with the outer-shell electron count.
Formula and working
Fill orbitals in Madelung (n+ℓ) order, maximum 2 electrons per orbital
- 1
Collect the inputs
Atomic number (Z) = 26
- 2
Apply the formula
Fill orbitals in Madelung (n+ℓ) order, maximum 2 electrons per orbital
- 3
Result
Ground-state configuration = 1s2 2s2 2p6 3s2 3p6 4s2 3d6
Frequently asked questions
Symbols and assumptions
- Z
- Atomic number
- n
- Principal quantum number (shell)
- ℓ
- Subshell type: s, p, d, f
- • The atom is neutral and in its ground state.
- • Filling follows the Madelung (n+ℓ) order except for listed experimental exceptions.
Sources and review
Reviewed 2026-09-22 · Next review 2027-09-22
- • Only well-established exceptions (such as Cr, Cu, Mo, Ag, Pt and Au) are corrected; ions and excited states are not covered.
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
Report a mistake or request an improvement
Tell us if a formula, unit, explanation, or result needs attention. Your message will include this calculator’s name and page.
Related calculators
Atom Calculator
Work out the protons, neutrons and electrons in an atom or ion from its atomic number, mass number and charge.
Atomic Mass Calculator
Estimate the mass number and the mass of a single atom in unified atomic mass units and kilograms.
Average Atomic Mass Calculator
Combine isotope masses and their natural abundances into the average atomic mass of an element.
Effective Nuclear Charge Calculator
Calculate the effective nuclear charge felt by an electron from the atomic number and the shielding constant.
Bond Order Calculator
Find the molecular-orbital bond order from the number of bonding and antibonding electrons.
Electronegativity Difference Calculator
Compare two Pauling electronegativity values to see whether a bond is non-polar, polar or ionic.