Electron Configuration Calculator

Electron Configuration Calculator

Results for Element :

Full Configuration:

Noble Gas Shorthand:

function calculateConfiguration() { var atomicNum = parseInt(document.getElementById("atomicNumber").value); var resultsArea = document.getElementById("resultsArea"); var fullDisplay = document.getElementById("fullConfig"); var shortDisplay = document.getElementById("shortConfig"); var resAtomicNum = document.getElementById("resAtomicNum"); if (isNaN(atomicNum) || atomicNum 118) { alert("Please enter a valid atomic number between 1 and 118."); return; } var orbitals = [ { name: "1s", cap: 2 }, { name: "2s", cap: 2 }, { name: "2p", cap: 6 }, { name: "3s", cap: 2 }, { name: "3p", cap: 6 }, { name: "4s", cap: 2 }, { name: "3d", cap: 10 }, { name: "4p", cap: 6 }, { name: "5s", cap: 2 }, { name: "4d", cap: 10 }, { name: "5p", cap: 6 }, { name: "6s", cap: 2 }, { name: "4f", cap: 14 }, { name: "5d", cap: 10 }, { name: "6p", cap: 6 }, { name: "7s", cap: 2 }, { name: "5f", cap: 14 }, { name: "6d", cap: 10 }, { name: "7p", cap: 6 } ]; var nobleGases = [ { symbol: "He", atomicNumber: 2, config: "1s²" }, { symbol: "Ne", atomicNumber: 10, config: "1s² 2s² 2p⁶" }, { symbol: "Ar", atomicNumber: 18, config: "1s² 2s² 2p⁶ 3s² 3p⁶" }, { symbol: "Kr", atomicNumber: 36, config: "1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶" }, { symbol: "Xe", atomicNumber: 54, config: "1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶" }, { symbol: "Rn", atomicNumber: 86, config: "1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶" }, { symbol: "Og", atomicNumber: 118, config: "…" } ]; function getFullConfig(num) { var remaining = num; var configParts = []; for (var i = 0; i < orbitals.length; i++) { if (remaining <= 0) break; var fill = Math.min(remaining, orbitals[i].cap); var sup = ""; var fillStr = fill.toString(); for(var j=0; j= 0; k–) { if (atomicNum > nobleGases[k].atomicNumber) { bestGas = nobleGases[k]; break; } else if (atomicNum === nobleGases[k].atomicNumber) { shorthand = "[" + nobleGases[k].symbol + "]"; break; } } if (shorthand === "" && bestGas) { var fullConfStr = getFullConfig(atomicNum); var gasConfStr = getFullConfig(bestGas.atomicNumber); var remainingStr = fullConfStr.replace(gasConfStr, "").trim(); shorthand = "[" + bestGas.symbol + "] " + remainingStr; } else if (shorthand === "" && atomicNum < 2) { shorthand = fullText; } resAtomicNum.innerText = atomicNum; fullDisplay.innerHTML = fullText; shortDisplay.innerHTML = shorthand; resultsArea.style.display = "block"; }

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What is Electron Configuration?

Electron configuration is the distribution of electrons of an atom or molecule in atomic or molecular orbitals. In chemistry, understanding how electrons are arranged is crucial because it determines the chemical behavior, reactivity, and bonding patterns of an element.

How to Use the Electron Configuration Calculator

1. Locate the Atomic Number of the element you are interested in using a Periodic Table (e.g., Oxygen is 8, Copper is 29).
2. Enter that number into the input field above.
3. Click "Generate Configuration" to see both the full string and the noble gas shorthand.

Key Rules for Filling Orbitals

This calculator follows the standard rules of quantum chemistry to determine the most stable (ground state) arrangement of electrons:

• Aufbau Principle: Electrons fill lower-energy orbitals first (1s, then 2s, then 2p, etc.).
• Pauli Exclusion Principle: An orbital can hold a maximum of 2 electrons, and they must have opposite spins.
• Hund's Rule: Every orbital in a subshell is singly occupied with one electron before any one orbital is doubly occupied.

Orbital Capacity Reference

Subshell Type	Number of Orbitals	Max Electrons
s (Sharp)	1	2
p (Principal)	3	6
d (Diffuse)	5	10
f (Fundamental)	7	14

Examples

Iron (Atomic Number 26):
Full: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁶
Shorthand: [Ar] 4s² 3d⁶

Iodine (Atomic Number 53):
Full: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁵
Shorthand: [Kr] 5s² 4d¹⁰ 5p⁵