Compounds of sodium like salt have been known since ancient times. Pure sodium was discovered by Sir Humpry Davy in 1807. He isolated pure sodium by using the electrolysis of caustic soda.
Atomic number: 11
Atomic weight: 22.990
Group, period, block: 1, 3, s
Color: silvery white metallic
Classification: alkali metal
Electron configuration: 3s1
Density: 0.968 g.m-3
Melting point: 370.87 K, 97.72 °C, 207.9 °F
Boiling point: 1156 K, 883 °C, 1621 °F
Oxidation states: +1, -1
Electronegativity: 0.93 (Pauling scale)
Ionization energies: 1st: 495.8 kJ·mol-1
Covalent radius: 166±9 pm
Van der Waals radius: 227 pm
There is one naturally occurring isotope of sodium exist, 23Na.