Element 11
Sodium (Na)
Sodium (Na) is element 11 of the periodic table, a alkali metal in period 3, group 1 (s-block) with an atomic mass of 22.99 and is a solid at standard conditions.
At a glance
- Atomic number
- 11
- Symbol
- Na
- Atomic mass
- 22.99 u
- Category
- Alkali metals
- Period
- 3
- Group
- 1
- Block
- s-block
- Phase at STP
- solid
Electron structure
- Electron configuration
- 1s2 2s2 2p6 3s1
- Shorthand configuration
- [Ne] 3s1
- Electrons per shell
- 2, 8, 1
- Oxidation states
- -1, +1
Physical properties
- Melting point
- 370.87 K
- Boiling point
- 1156 K
- Density
- 0.971 g/cm3
- Phase
- solid
Atomic properties
- Electronegativity (Pauling)
- 0.93
- Atomic radius
- 190 pm
- Covalent radius
- 166 pm
- Van der Waals radius
- 227 pm
- First ionization energy
- 496 kJ/mol
- Electron affinity
- 53 kJ/mol
Notable isotopes
| Isotope | Mass | Abundance | Stability |
|---|---|---|---|
| Na-23 | 22.98977 | 100% | Stable |
Common uses
- Table salt
- Street lamps
- Heat transfer
- Soap making
Discovery
- Year
- 1807
- Discovered by
- Humphry Davy
- Country
- England