Osmium

Symbol: Os
Atomic number: 76
Category: transition metals
Group: 8
Period: 6
Block: d
Atomic weight: 190.23 g/mol
Electrons per shell: 2, 8, 18, 32, 14, 2
CAS number: 7440-04-2
Phase: solid
Density: 22.61 kg/l (near room temperature)
Melting point: 3306 K (3033C, 5491F)
Boiling point: 5285 K (5012C, 9054F)
Crystal structure: hexagonal
Oxidation states: 8, 7, 6, 5, 4, 3, 2, 1, 0, -1, -2
Electronegativity: 2.2 (Pauling scale)
Name's origin: osme
Name's meaning: a Greek word for smell because of the smell of the volatile osmium tetroxide
Facts:
- the second densest element
- is used in alloys with platinum, iridium and other platinum group metals
- is found in nature as an alloy in platinum ore
- are employed in fountain pen tips, electrical contacts and in other applications where extreme durability and hardness are needed