Atoms of the same element are identical. The atoms of the one element are different from those of any other element. 3. Atoms of different elements can physically mix together or can chemically combine in simple whole-number ratios to form compounds.
iridium (symbol Ir) Silver-white, metallic element discovered in 1804 by the English chemist Smithson Tennant. A platinum-type metal, iridium is hard and brittle and the most corrosion-resistant metal. very rare element (0.0001 ppm of Earth 's crust), iridium is found in the naturally occurring alloys osmiridium (approximately 50% iridium) and iridiosmium (approximately 70% iridium) in Alaska and South Africa. It is obtained by igniting ammonium chloroiridate, (NH 4) 3 IrCl 6, in hydrogen atmosphere.
Word origin: Iridium comes from the Latin word iris, meaning rainbow. Discovery: British chemist Smithson Tennant discovered iridium in the residue left when crude platinum is dissolved by aqua regia in 1803. Properties of iridium. Iridium is the most corrosive resistant metal known and one of the densest metals.It is a member of the platinum family and is white with a yellowish tinge. Iridium is very hard and brittle, making it difficult to machine, form, or work.[See Periodic Table of the Elements ]. Sources of iridium.roperties of iridium. Iridium is the most corrosive resistant metal known and one of the densest metals. It is a member of the platinum family and is white with a yellowish tinge. Iridium is very hard and brittle, making it difficult to machine, form, or work. [See Periodic Table of the Elements ].