Name sodium
Symbol Na
Atomic Weight 22.989770
Atomic Number 11
CAS ID 7440-23-5
Group Number 1
Group Name Alkali Metal
Period Number 3
Origin of Name English, soda; Latin, natrium.
Year Discovered 1807
Discovery Credits Isolated by Sir Humphry Davy at the Royal Institution, London, UK.
Class Metallic
Color Silvery White
Standard State Solid at 77 F & 298 K
Description Soft, silvery white metal which oxidizes rapidly when cut. Reacts vigorously with water. Produced in large quantities and used as metal in heat exchanger in atomic reactors. NaCl is key industrial chemical, used to make Cl2, NaOH, etc.

Diagnostic tests: 
Compounds containing sodium give a strong and persistent yellow flame test. The test is so sensitive that sodium contamination may give a false positive.

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