What is "fermium"

fermium \fermium\ n. the transuranic element of atomic number 100; symbol Fm. The atomic weight of the most stable isotope, having a half-life of about 80 days, is 257. The first isotope, Fm255 was discovered in 1952 in the debris of a thermonuclear explosion. Other istopes have been produced in nuclear reactors and by decay of other transuranic elements.
--Handb. Ch. Phys. 61.

Syn: Fm.

radioactive element, discovered in the debris of a 1952 U.S. nuclear test in the Pacific, named 1955 for Italian-born U.S. physicist Enrico Fermi (1901-1954).

n. A transuranic chemical element (''symbol'' Fm) with an atomic number of 100.

n. a radioactive transuranic metallic element produced by bombarding plutonium with neutrons [syn: Fm, atomic number 100]

Fermium is a synthetic element with symbol Fm and atomic number 100. It is a member of the actinide series. It is the heaviest element that can be formed by neutron bombardment of lighter elements, and hence the last element that can be prepared in macroscopic quantities, although pure fermium metal has not yet been prepared. A total of 19 isotopes are known, with Fm being the longest-lived with a half-life of 100.5 days.

It was discovered in the debris of the first hydrogen bomb explosion in 1952, and named after Enrico Fermi, one of the pioneers of nuclear physics. Its chemistry is typical for the late actinides, with a preponderance of the +3 oxidation state but also an accessible +2 oxidation state. Owing to the small amounts of produced fermium and all of its isotopes having relatively short half-lives, there are currently no uses for it outside of basic scientific research.