Rhenium

Element Rhenium

It is a chemical element with the symbol Re and atomic number 75. It is a silvery-gray, heavy, third-row transition metal in group 7 of the periodic table.
Its usual commercial form is a powder, but this element can be consolidated by pressing and sintering in a vacuum or hydrogen atmosphere.
It can be prepared by many routes, a typical method is the reaction of Re2O7 and tetramethyltin:
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.

Rhenium has one stable isotope, rhenium-185, which nevertheless occurs in minority abundance, a situation found only in two other elements (indium and tellurium).
Naturally occurring rhenium is only 37.4% 185Re, and 62.6% 187Re, which is unstable but has a very long half-life (≈1010 years).