Periodic Table--Xenon

Xenon is a heavy rare gas with nine stable isotopes, ¹²⁴Xe, ¹²⁶Xe, ¹²⁸Xe, ¹²⁹Xe, ¹³⁰Xe, ¹³¹Xe, ¹³²Xe, ¹³⁴Xe and ¹³⁶Xe, five of which are radiogenic. ¹²⁹Xe is produced by beta decay of ¹²⁹I (half-life = 16 Myr); ¹³¹Xe, ¹³²Xe, ¹³⁴Xe and ¹³⁶Xe are fission products of both ²³⁸U and the extinct nuclide ²⁴⁴Pu. Because Xe is a tracer for two extinct nuclides, Xe isotopic ratios in meteorites are a powerful tool for studying the condensation of the solar system (Reynolds, 1963). The ¹²⁹I-¹²⁹Xe decay scheme has been used as a geochronometer based on the time-dependent decrease of the ratio of the radioactive ¹²⁹I to stable ¹²⁷I in the solar nebula. The I-Xe method of dating gives the time elapsed between nucleosynthesis and the condensation of a solid object from the solar nebula. Xenon isotopes are also a powerful tool for understanding terrestrial differentiation. Excess ¹²⁹Xe found in CO₂ well gases from New Mexico (Butler et al., 1963) was believed to have been derived by decay of mantle-derived gases soon after the formation of the Earth. Additional evidence for xenon isotopic evolution of mantle reservoirs has been obtained from MORBs (Staudacher and Allegre, 1982) and diamonds (Ozima and Zashu, 1991).

Source of text: This review was assembled by Eric Caldwell, primarily from Dicken (1995) and Faure (1986).