11
Na
Sodium
22.98976928
Sodium (Na)
Alkali MetalGroup 1Period 3s-block-block
Sodium /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.
Latin name: Natrium
Atomic Number
11
Atomic Mass
22.98976928 g/mol
Phase (STP)
Solid
Electron Config.
[Ne] 3s¹
General
SymbolNa
Atomic Number11
Atomic Mass22.98976928 g/mol
CategoryAlkali Metal
Group1
Period3
Blocks-block
Electron Configuration[Ne] 3s¹
Valence Electrons1
ColourSilvery-white
Appearancesilvery white metallic
CAS NumberCAS7440-23-5
Physical Properties
Phase (STP)Solid
Density0.971 g/cm³
Melting Point97.80°C · 208.04°F · 370.95 K
Boiling Point882.85°C · 1621.13°F · 1156.00 K
Atomic Properties
Atomic Radius190 pm
Covalent Radius166 pm
Van der Waals Radius227 pm
Electronegativity0.93 Pauling
Ionization Energy496 kJ/mol
Electron Affinity52.9 kJ/mol
Oxidation States+1
Ion ChargeNa⁺
Thermodynamic
Molar Heat28.23 J/(mol·K)
Thermal Conductivity140 W/(m·K)
Electromagnetic
Electrical TypeConductor
Crystal Structure
Crystal StructureBody-centered cubic
Mechanical Properties
Mohs Hardness0.5
Abundance
In Universe0.0020%
In Sun0.0004%
In Earth's Crust2.3000%
In Oceans1.1000%
In Humans0.1400%
In Meteorites0.5500%
Discovery & History
Discovery Year1807
Discovered ByHumphry Davy
Isotopes of Sodium
| Isotope | Abundance | Half-life | Decay |
|---|---|---|---|
| Na-22 | — | 2.6019 years | β⁺, EC |
| Na-23 | 100% | Stable | — |
| Na-24 | — | 14.957 hours | β⁻ |