1. By Elizabeth Cooper

2. The Basics Iridium has a melting point of 2410°C, boiling point of 4130°C, and valence of 3 or 4. It has 77 protons, 115 neutrons, 77 electrons, and 6 orbitals.

3. Appearance A member of the Platinum family, Iridium is white, but with a slight yellowish cast. The metal is very hard and brittle and is the most corrosion resistant metal known. Iridium is not attacked by acids, but is attacked by molten salts, including NaCl and NaCN. Either Iridium or Osmium is the densest known element.

4. Uses The metal is used for hardening Platinum. It is used in crucibles and other applications requiring high temperatures. Iridium is combined with Osmium to form an alloy used in compass bearings and for tipping pens. Iridium is also used for electrical contacts and in the jewelry industry.

5. Interesting Facts The word Iridium comes from the Latin iris (rainbow), because the salts of Iridium are highly colored. Discovered by Smithson Tennant, Antoine Fourcroy, Louis Vanquelin, and Hippolyte Collet-Descotils in 1803, France. The industrial extraction of iridium is complex as the metal occurs in ores mixed with other metals such as, Rhodium, Palladium, Silver, Platinum, and Gold.

6. A Poem About Iridium One of the least corrosive out there, Can get heated up without a care, Is also very dense, With excellent defense, It’s salts are really colorful, And also very beautiful, It’s very hard and brittle, It won’t get attacked by acids, Not even a little. It’s made by other metals, And breaks of like petals, It’s up there with Osmium, The element Iridium.

7. Resources (please click and wait for the “credits”) http://chemistry.about.com/library/blper5.htm http://www.chemicalelements.com/index.html http://chemistry.allinfoabout.com/periodic/periodictable.html http://www.webelements.com/webelements/scholar/elements/p eriodic-table/uses.html http://www.chemicool.com/ http://www.theodoregray.com/PeriodicTable/Elements/077/inde x.html T H E E N D