Sodium (Na): Electron Configuration, Properties and Uses
Sodium (Na): Electron Configuration, Properties and Uses
Electron configuration [Ne] 3s1 · group 1 · period 3 · Ar 22.99
Sodium data
- Atomic number
- 11
- Relative atomic mass
- 22.99
- Group
- 1
- Period
- 3
- Block
- s
- Category
- Alkali metal
- Electron configuration
- [Ne] 3s1
- Full configuration
- 1s2 2s2 2p6 3s1
- Electrons per shell
- 2, 8, 1 (K L M)
- Valence electrons
- 1
- Electronegativity (Pauling)
- 0.93
- First ionisation energy
- 5.139 eV
- Atomic radius (van der Waals)
- 227 pm
- State at room temperature
- Solid
- Melting point
- 97.8 °C
- Boiling point
- 883 °C
- Density
- 0.97 g/cm³
- Common oxidation states
- +1
- Discovered
- 1807
Source: PubChem (NIH, accessed 13 Nov 2026); atomic mass: IUPAC standard atomic weight.
Electron shell diagram
K 2 · L 8 · M 1
Orbital diagram (outer electrons)
About sodium
Sodium, symbol Na, is element number 11 in the periodic table. It is an alkali metal in group 1, period 3, s-block. The element was discovered in 1807. The symbol Na comes from the Latin natrium. Sodium is a solid at room temperature, melting at 97.8 °C and boiling at 883 °C. Its density of 0.97 g/cm³ is lower than water, so the metal floats.
Sodium electron configuration
The electron configuration of sodium is 1s2 2s2 2p6 3s1, or in short [Ne] 3s1. Its electrons occupy 3 shells: K = 2, L = 8, M = 1. Sodium has 1 valence electron in the M shell (3s1), which is why it sits in group 1. When it forms cations, electrons leave the outermost subshell first: Na+ = [Ne] (like neon).
Filling order: 1s2(2) → 2s2(4) → 2p6(10) → 3s1(11)
Uses of sodium
Well-known applications of sodium include table salt (NaCl), caustic soda (NaOH), baking soda (NaHCO3), sodium street lamps and sodium-ion batteries. For research and analysis you can browse sodium compounds in the AMI Scientific catalogue.
Safety
Sodium metal reacts violently with water, releasing hydrogen and heat, so it is stored under paraffin or mineral oil. Always read the safety data sheet (SDS) before working with a chemical.
Other elements in group 1
Frequently asked questions
What is the electron configuration of sodium?
The electron configuration of sodium (Na, atomic number 11) is 1s2 2s2 2p6 3s1, or [Ne] 3s1 in short. By shell: 2, 8, 1.
How many valence electrons does sodium have?
Sodium has 1 valence electron.
Which group and period is sodium in?
Sodium is in group 1, period 3, s-block.
What is the atomic mass of sodium?
The relative atomic mass of sodium is 22.99. Use it to calculate molar mass with the molar mass calculator.
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