Electron Configuration of Sodium (Na)
What is the electron configuration of Sodium?
The electron configuration of Sodium (Na, Z=11) is 1s² 2s² 2p⁶ 3s¹. In noble gas shorthand: [Ne] 3s¹. It has 1 unpaired electron(s) and is a s-block element.
| Symbol | Na |
| Atomic Number | 11 |
| Full Electron Configuration | 1s² 2s² 2p⁶ 3s¹ |
| Noble Gas Shorthand | [Ne] 3s¹ |
| Block | s |
| Period | 3 |
| Group | 1 |
| Unpaired Electrons | 1 |
| Exception? | No |
Orbital Filling Order
Following the aufbau principle, the 11 electrons in Sodium fill orbitals in order of increasing energy: 1s (2 electrons), then 2s (2 electrons), then 2p (6 electrons), then 3s (1 electron).
Each orbital is filled according to the Pauli exclusion principle (at most 2 electrons per orbital) and Hund's rule (electrons occupy degenerate orbitals singly before pairing).
Noble Gas Shorthand
The inner electrons of Sodium match the configuration of Ne. This allows us to abbreviate the configuration as [Ne] 3s¹, where [Ne] represents the filled core and the remaining entries show the valence electrons.
Valence Electrons
The valence shell of Sodium contains 1 electron in the 3s subshell. These outermost electrons determine Sodium's chemical reactivity, bonding behavior, and position in the periodic table as a s-block element in period 3.
Visualize orbital filling with 3D orbital shapes, aufbau principle, and noble gas shorthand for 36 elements.
Explore Sodium in the Electron Configuration ExplorerRelated Topics
Electron Configuration of Magnesium
Orbital filling and noble gas shorthand for Magnesium
Electron Configuration of Aluminum
Orbital filling and noble gas shorthand for Aluminum
Electron Configuration of Hydrogen
Orbital filling for Hydrogen (s-block)
Electron Configuration of Helium
Orbital filling for Helium (s-block)
Sodium on the Periodic Table
Full properties and periodic trends for Sodium
Orbital Hybridization
See how atomic orbitals mix to form sp, sp2, and sp3 hybrids