Find a neutral atom ground-state configuration
Select any element from hydrogen through oganesson to see its full electron configuration, noble-gas shorthand, electrons per principal shell, and outer-shell electron count. Atomic number supplies the electron total for a neutral atom. The orbitals fill with capacities s², p⁶, d¹⁰, and f¹⁴, following the usual increasing-energy sequence and documented ground-state exceptions.
For iron, atomic number 26, the full result ends 4s² 3d⁶ and the shorthand begins [Ar]. The bracketed noble gas replaces the complete configuration of the preceding closed shell; it does not remove those electrons from the atom. Shell totals provide a second view of the same electrons, while the orbital notation preserves subshell detail needed for bonding and periodic-trend questions.
Aufbau filling, Pauli capacity, and Hund context
The filling sequence orders subshell energies for the neutral ground-state model. No orbital can contain more than two electrons with opposite spin under the Pauli exclusion principle, and a subshell contains one orbital for s, three for p, five for d, and seven for f. This page reports subshell occupancy; it does not draw individual arrows or assign spin in each orbital.
Hund’s rule explains how electrons distribute among equal-energy orbitals before pairing, but it does not change the total p, d, or f superscript shown here. A result such as 2p⁴ still needs an orbital-box diagram if a question asks for unpaired electrons or magnetic behavior. Use the configuration as the starting total and apply the requested diagram convention separately.
Why some elements are exceptions
A simple diagonal filling mnemonic predicts many elements but not every measured ground state. Chromium and copper rearrange 4s and 3d occupancy; niobium through silver include several 5s/4d exceptions; selected lanthanides, platinum, gold, and actinides also differ from a naïve fill. The element list uses explicit exception data instead of presenting the mnemonic as an inviolable law.
Lawrencium is shown with the modern 7p¹ ground-state description used in current references rather than an older 6d¹ shorthand. Very heavy-element configurations can involve close energy levels and theoretical interpretation. When a course uses a different historical convention, identify that difference openly rather than assuming one typographic ending proves the other source is careless.
Check electron totals and shorthand
Add every superscript in the full configuration; the sum must equal the selected atomic number. Add the electrons-per-shell list and confirm the same total again. For shorthand, expand the bracketed noble gas and add the remaining superscripts. These three representations should agree even though their order and level of detail differ.
The reported outer-shell count includes electrons with the highest principal quantum number. That is useful for main-group patterns but is not a universal count of all electrons available for bonding. Transition metals can use nearby d electrons, and oxidation states require removing or adding electrons with ion-specific rules. Do not convert the outer-shell number automatically into a charge.
Neutral-atom limits and privacy
The calculator does not produce ion, excited-state, molecular-orbital, crystal-field, or relativistic wavefunction results. It is a transparent ground-state reference for learning element configurations. If a worksheet asks for an ion, begin with the neutral configuration and then follow the stated electron-removal or addition convention, paying special attention to transition-metal s electrons.
The values are calculated in the current browser tab. NexaCurrent does not upload the quantities, formulas, chemical names, element choices, or other information entered here, and no account is needed. Copying is a deliberate action after the answer and working are visible. Refreshing or leaving the page clears the current calculation, so keep a copied result if it is needed for later study.