11 Na Sodium 22.99
Alkali metal
Sodium 钠
[Ne] 3s¹
- Period 3
- Group 1
- Block s
- Solid
Electron configuration
1s² 2s² 2p⁶ 3s¹
Orbital diagram (valence)
3s ↑
- Electrons per shell
- 2, 8, 1
- Unpaired electrons
- 1
- Zeff (Slater)
- 2.20
Properties
- Atomic weight
- 22.99
- Electronegativity (Pauling)
- 0.93
- First ionization energy
- 495.8 kJ/mol
- Electron affinity
- 52.87 kJ/mol
- Covalent radius
- 166 pm
- van der Waals radius
- 227 pm
- Melting point
- 370.9 K
- Boiling point
- 1156 K
- Density
- 0.97 g/cm³
- Melting / boiling point
- 97.8 °C / 882.9 °C
- Common oxidation states
- +1
- Discovered
- 1807
Natural isotopes
| Mass number A | Abundance |
|---|---|
| 23Na | 100.00 % |
Isotope masses: AME2020; abundances: IUPAC/CIAAW representative values.
Emission spectrum
Sodium lamp · orange-yellow
Sodium flame · yellow
Successive ionization energies
The big jumps appear where core electrons start to be removed. Ionization energies from the NIST Atomic Spectra Database.
Sodium in the course
The lessons that discuss this element most (ranked by mentions).
- Reactions in aqueous solution Reactions and stoichiometry
- The glass pH electrode and ion-selective electrodes Electroanalytical chemistry
- Naming ions and compounds Reactions and stoichiometry
- Hydrogen and the s-block The main-group elements
- Atomic spectroscopy: emission and absorption Spectroscopic analysis
- Ionic bonding: opposite charges together Chemical bonds
- Ionic crystals: polyhedra and radius ratios Crystals and solids
- Conductometry: how fast ions move Electroanalytical chemistry
Lab experiments with Sodium
Crystal structures
- Body-centred cubic lattice parameter a = 429.1 pm
- Rock salt (NaCl type) lattice parameter a = 564.0 pm
Periodic trend
Group 1
Data: PubChem periodic table (public domain); atomic weights are IUPAC abridged standard values; covalent radii from Cordero et al. (2008).