Isotopes of rubidium
List of isotopes
Bold for isotopes with half-lives longer than the age of the universe (nearly stable) Abbreviations: EC: Electron capture IT: Isomeric transition Bold for stable isotopes Fission product Primordial radionuclide Used in rubidium–strontium dating

Isotopes of rubidium

Section Title: List of isotopes
Table Section Text: Bold for isotopes with half-lives longer than the age of the universe (nearly stable) Abbreviations: EC: Electron capture IT: Isomeric transition Bold for stable isotopes Fission product Primordial radionuclide Used in rubidium–strontium dating

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	decay mode(s)	daughter isotope(s)	nuclear spin and parity	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)

excitation energy

71Rb	37	34	70.96532(54)#	p	70Kr	5/2−#

72Rb	37	35	71.95908(54)#	<1.5 µs	p	71Kr	3+#

72mRb	100(100)# keV	1# µs	p	71Kr	1−#

73Rb	37	36	72.95056(16)#	<30 ns	p	72Kr	3/2−#

74Rb	37	37	73.944265(4)	64.76(3) ms	β+	74Kr	(0+)

75Rb	37	38	74.938570(8)	19.0(12) s	β+	75Kr	(3/2−)

76Rb	37	39	75.9350722(20)	36.5(6) s	β+	76Kr	1(−)

β+, α (3.8×10−7%)	72Se

76mRb	316.93(8) keV	3.050(7) µs	(4+)

77Rb	37	40	76.930408(8)	3.77(4) min	β+	77Kr	3/2−

78Rb	37	41	77.928141(8)	17.66(8) min	β+	78Kr	0(+)

78mRb	111.20(10) keV	5.74(5) min	β+ (90%)	78Kr	4(−)

IT (10%)	78Rb

79Rb	37	42	78.923989(6)	22.9(5) min	β+	79Kr	5/2+

80Rb	37	43	79.922519(7)	33.4(7) s	β+	80Kr	1+

80mRb	494.4(5) keV	1.6(2) µs	6+

81Rb	37	44	80.918996(6)	4.570(4) h	β+	81Kr	3/2−

81mRb	86.31(7) keV	30.5(3) min	IT (97.6%)	81Rb	9/2+

β+ (2.4%)	81Kr

82Rb	37	45	81.9182086(30)	1.273(2) min	β+	82Kr	1+

82mRb	69.0(15) keV	6.472(5) h	β+ (99.67%)	82Kr	5−

IT (.33%)	82Rb

83Rb	37	46	82.915110(6)	86.2(1) d	EC	83Kr	5/2−

83mRb	42.11(4) keV	7.8(7) ms	IT	83Rb	9/2+

84Rb	37	47	83.914385(3)	33.1(1) d	β+ (96.2%)	84Kr	2−

β− (3.8%)	84Sr

84mRb	463.62(9) keV	20.26(4) min	IT (>99.9%)	84Rb	6−

β+ (<.1%)	84Kr

85Rb	37	48	84.911789738(12)	Stable	5/2−	0.7217(2)

86Rb	37	49	85.91116742(21)	18.642(18) d	β− (99.9948%)	86Sr	2−

EC (.0052%)	86Kr

86mRb	556.05(18) keV	1.017(3) min	IT	86Rb	6−

87Rb	37	50	86.909180527(13)	4.923(22)×1010 y	β−	87Sr	3/2−	0.2783(2)

88Rb	37	51	87.91131559(17)	17.773(11) min	β−	88Sr	2−

89Rb	37	52	88.912278(6)	15.15(12) min	β−	89Sr	3/2−

90Rb	37	53	89.914802(7)	158(5) s	β−	90Sr	0−

90mRb	106.90(3) keV	258(4) s	β− (97.4%)	90Sr	3−

IT (2.6%)	90 Rb

91Rb	37	54	90.916537(9)	58.4(4) s	β−	91Sr	3/2(−)

92Rb	37	55	91.919729(7)	4.492(20) s	β− (99.98%)	92Sr	0−

β−, n (.0107%)	91Sr

93Rb	37	56	92.922042(8)	5.84(2) s	β− (98.65%)	93Sr	5/2−

β−, n (1.35%)	92Sr

93mRb	253.38(3) keV	57(15) µs	(3/2−,5/2−)

94Rb	37	57	93.926405(9)	2.702(5) s	β− (89.99%)	94Sr	3(−)

β−, n (10.01%)	93Sr

95Rb	37	58	94.929303(23)	377.5(8) ms	β− (91.27%)	95Sr	5/2−

β−, n (8.73%)	94Sr

96Rb	37	59	95.93427(3)	202.8(33) ms	β− (86.6%)	96Sr	2+

β−, n (13.4%)	95Sr

96mRb	0(200)# keV	200# ms [>1 ms]	β−	96Sr	1(−#)

IT	96Rb

β−, n	95Sr

97Rb	37	60	96.93735(3)	169.9(7) ms	β− (74.3%)	97Sr	3/2+

β−, n (25.7%)	96Sr

98Rb	37	61	97.94179(5)	114(5) ms	β−(86.14%)	98Sr	(0,1)(−#)

β−, n (13.8%)	97Sr

β−, 2n (.051%)	96Sr

98mRb	290(130) keV	96(3) ms	β−	97Sr	(3,4)(+#)

99Rb	37	62	98.94538(13)	50.3(7) ms	β− (84.1%)	99Sr	(5/2+)

β−, n (15.9%)	98Sr

100Rb	37	63	99.94987(32)#	51(8) ms	β− (94.25%)	100Sr	(3+)

β−, n (5.6%)	99Sr

β−, 2n (.15%)	98Sr

101Rb	37	64	100.95320(18)	32(5) ms	β− (69%)	101Sr	(3/2+)#

β−, n (31%)	100Sr

102Rb	37	65	101.95887(54)#	37(5) ms	β− (82%)	102Sr

β−, n (18%)	101Sr

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