Rhenium is a chemical element. It has the chemical symbol Re. It has the atomic number 75. It is a rare metal. It is silver white. In chemistry it is placed in a group of metal elements called the transition metals. The chemistry of rhenium is similar to manganese. Discovered in 1908, rhenium was the second-last stable element to be discovered ('stable' meaning not radioactive). It was named after the river Rhine in Europe.
Nickel-based superalloys of rhenium are used in the combustion chambers, turbine blades, and exhaust nozzles of jet engines. These alloys contain up to 6% rhenium, making jet engine construction the largest single use for the element. The second-most important use is as a catalyst: rhenium is an excellent catalyst for hydrogenation and isomerization.