Osmium

Symbol

Os

Atomic number

76

Atomic mass	190.2		Thermal conductivity	0.876
Atomic radius	1.92		Covalent radius	1.26
Density	22.57		Atomic volume	8.49
Melting point	3300		Oxidation states	2,3,4,6,8
Boiling point	5285		Stable isotopes	7
Heat of vapor.	746		Electronegativity	2.2
Heat of fusion	31.8		First ionization	8.7
Specific heat	0.13		Electrical conduct.	...

Electron configuration

Osmium

Osmium is an iron-gray metal, a member of the platinum group. Osmium forms the oxide OsO4 called osmic acid. It is a white crystalline powder which melts at 40°C and boils at about 100°C. It has a strong odor reminiscent of chlorine and is very poisonous. It can be reduced by organic matter and is used for staining of histological samples for microscope viewing. The reduction produces a metallic osmium structure which images the sample without distorting it.

Osmium has the distinction of being the most dense of all the naturally occuring elements at 22.57 gm/cm^3. This is almost twice the density of lead at 11.4 gm/cm^3.

Osmium is often associated with ruthenium.

Osmium Nuclear Data