Isotopes of strontium
List of isotopes
Abbreviations: EC: Electron capture IT: Isomeric transition Bold for stable isotopes, bold italic for nearly-stable isotopes (half-life longer than the age of the universe) Believed to decay by β⁺β⁺ to ⁸⁴Kr Used in rubidium–strontium dating Fission product

Isotopes of strontium

Section Title: List of isotopes
Table Section Text: Abbreviations: EC: Electron capture IT: Isomeric transition Bold for stable isotopes, bold italic for nearly-stable isotopes (half-life longer than the age of the universe) Believed to decay by β⁺β⁺ to ⁸⁴Kr Used in rubidium–strontium dating Fission product

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

73Sr	38	35	72.96597(64)#	>25 ms	β+ (>99.9%)	73Rb	1/2−#

β+, p (<.1%)	72Kr

74Sr	38	36	73.95631(54)#	50# ms [>1.5 µs]	β+	74Rb	0+

75Sr	38	37	74.94995(24)	88(3) ms	β+ (93.5%)	75Rb	(3/2−)

β+, p (6.5%)	74Kr

76Sr	38	38	75.94177(4)	7.89(7) s	β+	76Rb	0+

77Sr	38	39	76.937945(10)	9.0(2) s	β+ (99.75%)	77Rb	5/2+

β+, p (.25%)	76Kr

78Sr	38	40	77.932180(8)	159(8) s	β+	78Rb	0+

79Sr	38	41	78.929708(9)	2.25(10) min	β+	79Rb	3/2(−)

80Sr	38	42	79.924521(7)	106.3(15) min	β+	80Rb	0+

81Sr	38	43	80.923212(7)	22.3(4) min	β+	81Rb	1/2−

82Sr	38	44	81.918402(6)	25.36(3) d	EC	82Rb	0+

83Sr	38	45	82.917557(11)	32.41(3) h	β+	83Rb	7/2+

83mSr	259.15(9) keV	4.95(12) s	IT	83Sr	1/2−

84Sr	38	46	83.913425(3)	Observationally Stable	0+	0.0056(1)	0.0055–0.0058

85Sr	38	47	84.912933(3)	64.853(8) d	EC	85Rb	9/2+

85mSr	238.66(6) keV	67.63(4) min	IT (86.6%)	85Sr	1/2−

β+ (13.4%)	85Rb

86Sr	38	48	85.9092607309(91)	Stable	0+	0.0986(1)	0.0975–0.0999

86mSr	2955.68(21) keV	455(7) ns	8+

87Sr	38	49	86.9088774970(91)	Stable	9/2+	0.0700(1)	0.0694–0.0714

87mSr	388.533(3) keV	2.815(12) h	IT (99.7%)	87Sr	1/2−

EC (.3%)	87Rb

88Sr	38	50	87.9056122571(97)	Stable	0+	0.8258(1)	0.8229–0.8275

89Sr	38	51	88.9074507(12)	50.57(3) d	β−	89Y	5/2+

90Sr	38	52	89.907738(3)	28.90(3) y	β−	90Y	0+

91Sr	38	53	90.910203(5)	9.63(5) h	β−	91Y	5/2+

92Sr	38	54	91.911038(4)	2.66(4) h	β−	92Y	0+

93Sr	38	55	92.914026(8)	7.423(24) min	β−	93Y	5/2+

94Sr	38	56	93.915361(8)	75.3(2) s	β−	94Y	0+

95Sr	38	57	94.919359(8)	23.90(14) s	β−	95Y	1/2+

96Sr	38	58	95.921697(29)	1.07(1) s	β−	96Y	0+

97Sr	38	59	96.926153(21)	429(5) ms	β− (99.95%)	97Y	1/2+

β−, n (.05%)	96Y

97m1Sr	308.13(11) keV	170(10) ns	(7/2)+

97m2Sr	830.8(2) keV	255(10) ns	(11/2−)#

98Sr	38	60	97.928453(28)	0.653(2) s	β− (99.75%)	98Y	0+

β−, n (.25%)	97Y

99Sr	38	61	98.93324(9)	0.269(1) s	β− (99.9%)	99Y	3/2+

β−, n (.1%)	98Y

100Sr	38	62	99.93535(14)	202(3) ms	β− (99.02%)	100Y	0+

β−, n (.98%)	99Y

101Sr	38	63	100.94052(13)	118(3) ms	β− (97.63%)	101Y	(5/2−)

β−, n (2.37%)	100Y

102Sr	38	64	101.94302(12)	69(6) ms	β− (94.5%)	102Y	0+

β−, n (5.5%)	101Y

103Sr	38	65	102.94895(54)#	50# ms [>300 ns]	β−	103Y

104Sr	38	66	103.95233(75)#	30# ms [>300 ns]	β−	104Y	0+

105Sr	38	67	104.95858(75)#	20# ms [>300 ns]

Sentence(s)

The strontium-89 (⁸⁹Sr) has a half-life of 50.57 days.

final_sentence: The strontium-89 (⁸⁹Sr) has a half-life of 50.57 days.