Periodic Table ~ tungsten ~ Element ~ CAS 7440-33-7

tungsten

Name	tungsten
Symbol	W
Atomic Weight	183.84
Atomic Number	74
CAS ID	7440-33-7
Group Number	6
Group Name	(none)
Period Number	6
Origin of Name	Swedish, tung sten = "heavy stone."
Year Discovered	1783
Discovery Credits	Isolated by J. J. and F. Elhuijar at Vergara, Spain.
Class	Metallic
Color	Grayish White, Lustrous
Standard State	Solid at 77 F & 298 K
Description	Obtained as dull gray powder, difficult to melt. Metal is lustrous and silvery white. Resists attack by oxygen, acids, and alkalis. Used in alloys, light bulb filaments, and cutting tools. Diagnostic tests: Wolframates (Tungstates )(WO₄^2-): When the mineral is decomposed by boiling in HCL, the insoluble WO₃ canary yellow oxide is obtained. Tungsten gives a Na₂(NH₄)(PO₄) bead a clear (no) color in the oxidizing flame and a fine blue color in the reducing flame.