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Sodium (Na)

Sodium is a chemical element of the periodic table with chemical symbol Na and atomic number 11 with an atomic weight of 22.9898 u and is classed as alkali metal and is part of group 1 (alkali metal). Sodium is solid at room temperature.

Sodium in the periodic table

Atomic number11
Group1 (Alkali metal)
ClassificationAlkali Metal
AppearanceSilvery white metallic
Color Silver
Number of protons11 p+
Number of neutrons12 n0
Number of electrons11 e-
From Wikipedia, the free encyclopediaSodium /ˈsoʊdiəm/ is a chemical element with symbol Na (from Ancient Greek Νάτριο) and atomic number 11. It is a soft, silver-white, highly reactive metal. In the Periodic table it is in column 1 (alkali metals), and shares with the other six elements in that column that it has a single electron in its outer shell, which it readily donates, creating a positively charged atom - a cation.

Physical properties

Phase at STPSolid
Density0.968 g/cm3
Atomic weight22.9898 u

Thermal properties

Melting point370.944 K
97.794 °C
208.0292 °F
Boiling point1156.09 K
882.94 °C
1621.292 °F
Heat of vaporization98.01 kJ/mol

Atomic properties

Electronegativity (Pauling Scale)0.93
Electron affinity52.867 kJ/mol
Oxidation states−1, +1
(a strongly basic oxide)
Ionization energies
  1. 495.8 kJ/mol
  2. 4562 kJ/mol
  3. 6910.3 kJ/mol
  4. 9543 kJ/mol
  5. 13354 kJ/mol
  6. 16613 kJ/mol
  7. 20117 kJ/mol
  8. 25496 kJ/mol
  9. 28932 kJ/mol
  10. 141362 kJ/mol
  11. 159076 kJ/mol

Electron configuration for sodium

Electron configuration
Shorthand configuration
[Ne] 3s1
Electron configuration
Full configuration
1s2 2s2 2p6 3s1
Electron configuration chart
Electrons per shell2, 8, 1
Valence electrons 1
Valency electrons 1
Bohr model
SodiumElectron shell for Sodium, created by Injosoft ABNa
Figure: Shell diagram of Sodium (Na) atom.
Orbital Diagram

The history of Sodium

Discovery and first isolationHumphry Davy (1807)
Discovery of sodium
In medieval Europe, a compound of sodium with the Latin name of sodanum was used as a headache remedy. The name sodium is thought to originate from the Arabic suda, meaning headache, as the headache-alleviating properties of sodium carbonate or soda were well known in early times. Although sodium, sometimes called soda, had long been recognized in compounds, the metal itself was not isolated until 1807 by Sir Humphry Davy through the electrolysis of sodium hydroxide. In 1809, the German physicist and chemist Ludwig Wilhelm Gilbert proposed the names Natronium for Humphry Davy's "sodium" and Kalium for Davy's "potassium". The chemical abbreviation for sodium was first published in 1814 by Jöns Jakob Berzelius in his system of atomic symbols, and is an abbreviation of the element's New Latin name natrium, which refers to the Egyptian natron, a natural mineral salt mainly consisting of hydrated sodium carbonate.


List of unique identifiers for Sodium in various chemical registry databases
CAS Number7440-23-5
ChemSpider ID4514534
EC number231-132-9
PubChem CID Number5360545