Isotopes of barium Isotopes of barium Naturally occurring barium (Ba) is a mix of six stable isotopes and one very long-lived radioactive primordial isotope, barium-130, recently identified as being unstable by geochemical means (from analysis of the presence of its daughter xenon-130 in rocks). This nuclide decays by double-electron capture (absorbing two electrons and emitting two neutrinos); with a half-life of (0.5–2.7)×10 years (about 10 times the age of the universe). There are a total of thirty-three known radioisotopes in addition to Ba, but most of these are highly radioactive with half-lives in the several millisecond to several minute range. The only notable
Silver steel Silver steel Silver steel is common tool steel that is supplied as a centerless ground round bar (with tolerances similar to that of drill bit). The name comes from the highly polished appearance of the rods; there is no silver in the alloy. Amongst other applications, it has been widely used to make such things as punches, engravers, screwdrivers. Sheffield silver steel is used in France as a blade steel for straight razors. In Finland, German silver steel was and still is widely used for Puukko knives. The composition is defined by UK specification BS-1407, and is given below. In