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 Free Online Electronic Configuration Tool

100% Free | Unlimited Use | No Sign-Up Required

Get electronic configurations of all 118 elements — Easy, Fast & Accurate!

⚛️ Electronic Configuration (spdf)

🔍 Electron Configuration Exceptions (Important for NEET, JEE, Class 11–12)

Atomic No. Element Expected Configuration Actual Configuration Reason
24 Chromium (Cr) [Ar] 4s² 3d⁴ [Ar] 4s¹ 3d⁵ Half-filled d⁵ is more stable
29 Copper (Cu) [Ar] 4s² 3d⁹ [Ar] 4s¹ 3d¹⁰ Fully filled d¹⁰ is more stable
42 Molybdenum (Mo) [Kr] 5s² 4d⁴ [Kr] 5s¹ 4d⁵ Half-filled d⁵ stability
46 Palladium (Pd) [Kr] 5s² 4d⁸ [Kr] 4d¹⁰ No 5s electron; d¹⁰ full stability
47 Silver (Ag) [Kr] 5s² 4d⁹ [Kr] 5s¹ 4d¹⁰ Full d¹⁰ preferred
79 Gold (Au) [Xe] 6s² 4f¹⁴ 5d⁹ [Xe] 6s¹ 4f¹⁴ 5d¹⁰ Full d orbital stability
Atomic Number Element Electronic Configuration
1Hydrogen (H)1s¹
2Helium (He)1s²
3Lithium (Li)1s² 2s¹
4Beryllium (Be)1s² 2s²
5Boron (B)1s² 2s² 2p¹
6Carbon (C)1s² 2s² 2p²
7Nitrogen (N)1s² 2s² 2p³
8Oxygen (O)1s² 2s² 2p⁴
9Fluorine (F)1s² 2s² 2p⁵
10Neon (Ne)1s² 2s² 2p⁶
11Sodium (Na)1s² 2s² 2p⁶ 3s¹
12Magnesium (Mg)1s² 2s² 2p⁶ 3s²
13Aluminium (Al)1s² 2s² 2p⁶ 3s² 3p¹
14Silicon (Si)1s² 2s² 2p⁶ 3s² 3p²
15Phosphorus (P)1s² 2s² 2p⁶ 3s² 3p³
16Sulfur (S)1s² 2s² 2p⁶ 3s² 3p⁴
17Chlorine (Cl)1s² 2s² 2p⁶ 3s² 3p⁵
18Argon (Ar)1s² 2s² 2p⁶ 3s² 3p⁶
19Potassium (K)1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹
20Calcium (Ca)1s² 2s² 2p⁶ 3s² 3p⁶ 4s²
21Scandium (Sc)1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹ 4s²
22Titanium (Ti)1s² 2s² 2p⁶ 3s² 3p⁶ 3d² 4s²
23Vanadium (V)1s² 2s² 2p⁶ 3s² 3p⁶ 3d³ 4s²
24Chromium (Cr)1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s¹
25Manganese (Mn)1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s²
26Iron (Fe)1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁶ 4s²
27Cobalt (Co)1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁷ 4s²
28Nickel (Ni)1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁸ 4s²
29Copper (Cu)1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s¹
30Zinc (Zn)1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s²

In the world of chemistry, understanding how electrons are arranged around the nucleus of an atom is key to unlocking the mysteries of chemical bonding, atomic behavior, and the periodic table. This arrangement is known as electronic configuration.

The electronic configuration of an element describes the distribution of electrons in atomic orbitals. It provides insights into the chemical properties of elements and plays a crucial role in predicting chemical reactions and trends in the periodic table.

Whether you’re a class 11 or 12 student, or preparing for NEET or JEE, mastering electronic configuration is a foundational skill.

Why is Electronic Configuration Important?

  • Predicts chemical reactivity of elements
  • Determines valency and bonding behavior
  • Explains the position of elements in the periodic table
  • Helps in understanding ion formation
  • Crucial for JEE/NEET chemistry questions
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