Isotopes of the Element Selenium
[Click for Main Data]

Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information.

Isotopes of the Element Selenium with a Known Natural Abundance

Mass Number	Natural Abundance	Half-life

74	0.89%	Stable

76	9.37%	Stable

77	7.63%	Stable

78	23.77%	Stable

80	49.61%	Stable

82	8.73%	0.83×10⁺²⁰ years

All Known Isotopes of the Element Selenium

Mass Number	Half-life	Decay Mode	Branching Percentage

65	< 50 milliseconds	Electron Capture	100.00

66	> 1.2 microseconds	Electron Capture	100.00

67	60 milliseconds	Electron Capture	100.00

		Electron Capture with delayed Proton Emission	0.50

68	35.5 seconds	Electron Capture	100.00

69	27.4 seconds	Electron Capture	100.00

		Electron Capture with delayed Proton Emission	0.05

70	41.1 minutes	Electron Capture	100.00

71	4.74 minutes	Electron Capture	100.00

72	8.40 days	Electron Capture	100.00

73	7.15 hours	Electron Capture	100.00

73_m	39.8 minutes	Isomeric Transition	72.60

		Electron Capture	27.40

74	Stable	-	-

75	119.779 days	Electron Capture	100.00

76	Stable	-	-

77	Stable	-	-

77_m	17.36 seconds	Isomeric Transition	100.00

78	Stable	-	-

79	2.95×10⁺⁵ years	Beta-minus Decay	100.00

79_m	3.92 minutes	Isomeric Transition	99.94

		Beta-minus Decay	0.06

80	Stable	-	-

81	18.45 minutes	Beta-minus Decay	100.00

81_m	57.28 minutes	Isomeric Transition	99.95

		Beta-minus Decay	0.05

82	0.83×10⁺²⁰ years	Double Beta-minus Decay	100.00

83	22.3 minutes	Beta-minus Decay	100.00

83_m	70.1 seconds	Beta-minus Decay	100.00

84	3.10 minutes	Beta-minus Decay	100.00

85	31.7 seconds	Beta-minus Decay	100.00

86	15.3 seconds	Beta-minus Decay	100.00

87	5.50 seconds	Beta-minus Decay	100.00

		Beta-minus Decay with delayed Neutron Emission	0.20

88	1.53 seconds	Beta-minus Decay	100.00

		Beta-minus Decay with delayed Neutron Emission	0.99

89	0.41 seconds	Beta-minus Decay	100.00

		Beta-minus Decay with delayed Neutron Emission	7.80

90	> 150 nanoseconds	Beta-minus Decay	No Data Available

91	0.27 seconds	Beta-minus Decay	100.00

		Beta-minus Decay with delayed Neutron Emission	21.00

92	No Data Available	Beta-minus Decay	100.00

93	> 150 nanoseconds	Beta-minus Decay	No Data Available

94	> 150 nanoseconds	Beta-minus Decay	No Data Available

This page is maintained by Steve Gagnon.

Citation and linking information

Isotopes of the Element Selenium[Click for Main Data]

Isotopes of the Element Selenium
[Click for Main Data]