Barium green color. Barium sulfate is used as an insoluble additive to oil well drilling fluid, as well as in a purer form, as X-ray radiocontrast agents for imaging the human gastrointestinal tract. The soluble barium ion and soluble compounds are poisonous, and have been used as rodenticides. Barium is a soft, silvery-white metal, with a slight golden shade when ultrapure. The silvery-white color of barium metal rapidly vanishes upon oxidation in air yielding a dark gray oxide layer. Barium has a medium specific weight and good electrical conductivity. Ultrapure barium is very difficult to prepare, and therefore many properties of
Isotopes of barium exceptions are Ba, which has a half-life of 10.51 years, Ba (11.5 days), and Ba (2.55 minutes), which is the decay product of Cs (30.17 years, and a common fission product). Barium-114 is predicted to undergo cluster decay, emitting a nucleus of stable C to produce Sn. However this decay is not yet observed; the upper limit on the branching ratio of such decay is 0.0034%. 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