Sodium or natrium

Symbol: Na
Atomic number: 11
Category: alkali metals
Group: 1
Period: 3
Block: s
Atomic weight: 22.98976928 g/mol
Electrons per shell: 2, 8, 1
CAS number: 7440-23-5
Phase: solid
Density: 0.968 kg/l (near room temperature)
Melting point: 370.87 K (97.72C, 207.9F)
Boiling point: 1156 K (883C, 1621F)
Crystal structure: cubic body centered
Oxidation states: 1
Electronegativity: 0.93 (Pauling scale)
Name's origin (sodium): suda
Name's meaning: headache, as the headache curing properties of sodium carbonate or soda were well known in early times
Name's origin (natrium): natron
Name's meaning: a natural mineral salt whose primary ingredient is hydrated sodium carbonate
Facts:
- appears always as chemical compounds in natu- re, never in its elemental form
- potentially explosive in water; the reaction temperature sets the forming hydrogen gas in flames
- a soft, light metal