Iridium

Kelsey TaylorCHE: 120-010

Element Project

Basic Information

Symbol: IrAtomic mass: 192.22 amuTransition metalAtomic number: 77

History of Iridium

Discovered in 1803 by Smithson Tennant (English; Yorkshire, England)

It was found in the residue left behind by platinum when it dissolved in a mixture of hydrochloric acid and nitric acid.

The term Iridium comes from the Latin term “iris” (rainbow) because many of the salts found within Iridium were brightly colored.

Smithson Tennant

Properties of Ir

Iridium is a solid at room temperature.Color: whiteBoiling point: 4703 K (4430˚C)Melting point: 2720 K (2447˚C)Density: 22.56 g/cm³ (at 293 K)The most common isotope of Iridium is

193Ir and the most stable are 193Ir and 191Ir

Uses of Ir

Iridium is mainly used in platinum alloys as a hardening agent.

It is also used in making crucibles and making equipment that is used at high temperatures, heavy-duty electrical contacts, and in the tips of pens.

Radioactive isotopes are used in cancer treatment in radiation therapy.

Availability of Ir

Iridium is found with platinum and osmium in alluvial deposits in many alloys

It is also recovered as a by-product in the nickel mining industry

Cost: $2300 for 100g in bulk

Resources

http://www.chemicool.com/elements/iridium.html

http://www.chemicalelements.com/elements/ir.html

http://www.facts-about.org.uk/science-element-iridium.htm