Sodium

Document v1 · published by Koskamo · updated 2026-10-04

Sodium (Na) is chemical element 11, an alkali metal in group 1, period 3 (PubChem).

Atomic number: 11
Symbol: Na
Group: 1
Period: 3
Atomic mass: 22.9897693 u
Electron configuration: [Ne]3s1
Electronegativity (Pauling scale): 0.93
Atomic radius (van der Waals): 227 pm
Ionization energy: 5.139 eV
Electron affinity: 0.548 eV
Oxidation states: +1
Standard state: Solid
Melting point: 370.95 K
Boiling point: 1156 K
Density: 0.97 g/cm³
Chemical group: Alkali metal
Year discovered: 1807

Source and provenance

Original source: pubchem.ncbi.nlm.nih.gov
Published on Koskamo by: Koskamo
Citation version: Document v1
Reuse: PubChem periodic table data (NIH/NLM, pubchem.ncbi.nlm.nih.gov/ptable); group and period from Jefferson Lab via PubChem

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Version history

Published by Koskamo2026-10-04
Version 1