Notable Isotopes 
78Kr [42 neutrons]
Abundance: 0.35%
Half life: 2.3 x 1020 years [ Double Electron Capture ]
Decay Energy: ? MeVDecays to 78Se.
79Kr [43 neutrons]Abundance: synthetic
Half life: 35.04 hours [ Electron Capture ]
Decay Energy: ? MeVDecays to 79Br.
Half life: 35.04 hours [ beta+ ]
Decay Energy: 0.604 MeVDecays to 79Br.
Half life: 35.04 hours [ Gamma Radiation ]
Decay Energy: 0.26, 0.39, 0.60 MeVDecays to ?.
80Kr [44 neutrons]Abundance: 2.25%
Stable with 44 neutrons
Half life: 44
81Kr [45 neutrons]Abundance: synthetic
Half life: 2.29 x 105 years [ Electron Capture ]
Decay Energy: ? MeVDecays to 81Br.
Half life: 2.29 x 105 years [ Gamma Radiation ]
Decay Energy: 0.281 MeVDecays to ?.
82Kr [46 neutrons]Abundance: 11.6%
Stable with 46 neutrons
83Kr [47 neutrons]Abundance: 11.5%
Stable with 47
84Kr [48 neutrons]Abundance: 57%
Stable with 48 neutrons
85Kr [49 neutrons]Abundance: synthetic
Half life: 10.756 years [ beta- ]
Decay Energy: 0.687 MeVDecays to 85Rb.
| 85Kr is an inert radioactive noble gas with a half-llife of 10.76 years. It is produced by the fission of uranium and plutonium, such as in nuclear bomb testing and nuclear reactors. 85Kr is released during the reprocessing of fuel rods from nuclear reactors. Concentrations at the North Pole are 30% higher than at the South Pole as most nuclear reactors are in the northern hemisphere. |
86Kr [50 neutrons]Abundance: 17.3%
Stable with 50 neutrons