Sodium (Na)
Sodium (Na) is element 11, an alkali metal. Atomic mass 22.98976928, configuration [Ne] 3s¹. Properties, isotopes, oxidation states, uses and history, with an interactive 3D atom model.
Key facts
| Atomic number | 11 |
|---|---|
| Symbol | Na |
| Standard atomic weight | 22.98976928(2) |
| Category | Alkali Metal |
| Group | 1 |
| Period | 3 |
| State at room temperature | Solid |
| Electron configuration | [Ne] 3s¹ |
| Valence electrons | 1 |
| Common oxidation states | +1 |
| Common ions | Na⁺ |
| Electronegativity (Pauling) | 0.93 |
| First ionization energy | 496 kJ/mol |
| Electron affinity | 52.87 kJ/mol |
| Atomic radius | 190 pm |
| Density | 0.97 g/cm³ |
| Melting point | 97.78°C |
| Boiling point | 883°C |
| Specific heat | 1.228 J/(g·°C) |
Natural isotopes
- Na-23: Stable
Common uses
- Table salt (NaCl)
- Street lights
- Soap making
Where it matters
- Human biology (Nerve impulses)
- Nuclear reactors (Coolant in fast breeders)
Hazards
- Reacts violently with water
History
| Discovered | 1807 |
|---|---|
| Discovered by | Humphry Davy |
| Name | Humphry Davy |