Barium hydroxide, it absorbs very little CO in aqueous solutions and is therefore insensitive to atmospheric fluctuations. This property is used in calibrating pH equipment. Volatile barium compounds burn with a green to pale green flame, which is an efficient test to detect a barium compound. The color results from spectral lines at 455.4, 493.4, 553.6, and 611.1 nm. Organobarium compounds are a growing field of knowledge: recently discovered are dialkylbariums and alkylhalobariums. Barium found in the Earth's crust is a mixture of seven primordial nuclides, barium-130, 132, and 134 through 138. Barium-130 undergoes very slow radioactive decay to xenon-130 by
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