Osmium (Os)
| Atomic Number | 76 |
|---|---|
| Atomic Mass | 190.233 u |
| Category | Transition metal |
| Electron Config | [Xe] 4f¹⁴ 5d⁶ 6s² |
| Appearance | silvery, blue cast |
| Density (STP) | 22590 g/L |
| Melting Point | 3306 K |
| Boiling Point | 5285 K |
| Electronegativity | 2.2 (Pauling) |
| Ionization Energy | 840 kJ/mol |
| Atomic Radius | 130 pm |
| Crystal Structure | Simple Hexagonal |
| Discovered By | Smithson Tennant (1803) |
Brief Introduction
Osmium (Os) is a rare, lustrous, silvery-white transition metal, extremely dense, and one of the densest elements known. It is very hard, brittle, and has the highest melting point of the platinum group metals. Key details about Osmium (Os) are as follows:
Uses: Primarily used in alloys with platinum and iridium to make fountain pen nibs, electrical contacts, and styluses for record players (due to its hardness and corrosion resistance). It is also used in some specialized high-temperature applications and as a catalyst.
Production/Extraction: It is extremely rare, with an average crustal abundance of only about 0.0015 parts per million. It is primarily obtained as a byproduct of platinum and nickel refining, as it occurs in trace amounts in platinum-bearing ores.
History: Discovered in 1803 by Smithson Tennant in London, England. He named it from the Greek word "osme" (smell) because of the pungent, irritating odor of its volatile oxide, osmium tetroxide.
Health Effects & Safety: Osmium metal itself is relatively inert, but osmium tetroxide (OsO₄) is highly toxic, volatile, and corrosive. It can cause severe eye irritation, respiratory problems, and skin damage. Strict handling procedures are required when working with osmium compounds.
Price/Market: One of the rarest and most expensive metals, with prices driven by its scarcity and specialized applications. Supply is limited and dependent on platinum group metal mining.
Properties: It is the densest naturally occurring element (22.59 g/cm³), has a very high melting point (3033°C), is extremely hard, and is highly resistant to corrosion. It forms a volatile oxide that is toxic.
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