A frequently occurring chemical element is a silvery alkali metal. It is a pure element the only stable isotope o f which is Na.
Atomic number 11
Atomic weight 22.9898
Specific thermal weight at 20°C 0.968 g/cm3
Melting point 97.72°C
Boiling point 883°C
Melting heat 115 kJ/kg
Specific thermal capacity at 20°C 1.20kJ/(kg · K)
Thermal conductivity 103kJ/(m · K)
Therm. coefficient for linear expansion 72 10-6/K
Coefficient for linear expansion
Today, large-scalesodium production takes place by means of fused-salt electrolysis of dry sodium chloride in a so-called Downs cell.
In humid air, sodium develops a cover of consisting of a hydroxide carbonate mixture and reacts with water rather vigorously to form hydroxide solution. It should therefore be stored under petroleum.
Today, sodium is easier to handle as it is available in vacuum packaging with a net weight of 10g, 20g, 50g, and 100g. Sodium is used as a modifier for aluminum-silicone cast alloys.