Osmium was discovered by English chemist Smithson Tennant in London in the year 1803. His discovery of osmium took shape when he dissolved a sample of crude platinum in aqua regia, a mixture of hydrochloric acid and nitric acid. The process resulted in a metallic, black powder.
Older chemists were of the opinion that this powder was graphite, but Tennant thought differently. He treated the powder with sodium hydroxide and heated the solution. He then removed an alkali from the residue by mixing it with water. Tennant then added hydrochloric acid to the remaining residue to form an acidic solution. He observed that the alkaline solution contained osmium, whereas the acidic solution contained iridium. Osmium tetroxide, OsO4, which was formed in this reaction was highly toxic and had a bad odour. Because of this, Tennant named the element after the Greek word for smell, osme.
Osmium-platinum alloys are used in the manufacturing of pacemaker electrodes as they are highly resistant to corrosion.
Picture Credit : Google
