Isotopes of indium

Indium (₄₉In) consists of two primordial nuclides, with the most common (95.7%) nuclide (¹¹⁵In) being measurably though weakly radioactive. Its spin-forbidden decay has a half-life of 4.41×10¹⁴ years, much longer than the currently accepted age of the Universe.

Isotopes of indium (₄₉In)

Main isotopes[1] Decay abun­dance half-life (t1/2) mode pro­duct 111In synth 2.8048 d ε 111Cd 113In 4.28% stable 115In 95.7% 4.41×1014 y β− 115Sn
Standard atomic weight Ar°(In)
	114.818±0.001[2] 114.82±0.01 (abridged)[3]
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The stable isotope ¹¹³In is only 4.3% of naturally occurring indium. Among elements with a known stable isotope, only tellurium and rhenium also have all stable isotopes in lower abundance than a long-lived radioactive isotope, but the discrepancy is not so striking. Other than ¹¹⁵In, the longest-lived radioisotope is ¹¹¹In, with a half-life of 2.8048 days. All other radioisotopes have half-lives less than 5 hours. This element also has 47 isomers, the longest-lived being ^114m1In, with a half-life of 49.51 days. All other meta-states have half-lives also less than 5 hours.

Indium-111 is used medically in nuclear imaging, as a radiotracer nuclide tag for gamma camera localization of protein radiopharmaceuticals, such as In-111-labeled octreotide, which binds to receptors on certain endocrine tumors (Octreoscan).^[4] Indium-111 is also used in indium white blood cell scans, which use nuclear medical techniques to search for hidden infections.

Several proton-rich isotopes of indium have been used to help measure the mass of the doubly-magic isotope tin-100.^[5][6]

List of isotopes

Nuclide [n 1]	Z	N	Isotopic mass (Da) [n 2][n 3]	Half-life [n 4]	Decay mode [n 5]	Daughter isotope [n 6][n 7]	Spin and parity [n 8][n 4]	Natural abundance (mole fraction)
	Excitation energy[n 4]							Normal proportion	Range of variation
96In	49	47	95.95911(54)#	1# ms [>400 ns]	β+?	96Cd	9/2+#
					p?	95Cd
97In	49	48	96.94913(43)#	36(6) ms	β+ (97.7%)	97Cd	9/2+#
					β+, p (2.3%)	96Ag
					p?	96Cd
97mIn	400(100)# keV			0.12(7) ms	p?	96Cd	1/2−#
98In	49	49	97.94213(33)#	30(1) ms	β+ (>99.87%)	98Cd	(0+)
					β+, p (<0.13%)	97Ag
98mIn[n 9]	820(730) keV			890(20) ms	β+ (56%)	98Cd	(9+)
					β+, p (44%)	97Ag
99In	49	50	98.93411(32)#	3.11(6) s	β+ (99.71%)	99Cd	9/2+#
					β+, p (0.29%)	98Ag
100In	49	51	99.9311019(24)	5.62(6) s	β+ (98.34%)	100Cd	6+#
					β+, p (1.66%)	99Ag
101In	49	52	100.926414(13)	15.1(11) s	β+ (>98.3%)	101Cd	(9/2+)
					β+, p (<1.7%)	100Ag
101mIn	640(40) keV			10# s	β+?	101Cd	1/2−#
					IT?	101In
102In	49	53	101.9241059(49)	23.3(1) s	β+ (99.99%)	102Cd	(6+)
					β+, p (0.0093%)	101Ag
103In	49	54	102.9198788(96)	60(1) s	β+	103Cd	(9/2+)
103mIn	631.7(1) keV			34(2) s	β+ (67%)	103Cd	(1/2−)
					IT (33%)	103In
104In	49	55	103.9182145(62)	1.80(3) min	β+	104Cd	(5+)
104mIn	93.48(10) keV			15.7(5) s	IT (80%)	104In	(3+)
					β+ (20%)	104Cd
105In	49	56	104.914502(11)	5.07(7) min	β+	105Cd	9/2+
105mIn	674.09(25) keV			48(6) s	IT	105In	(1/2)−
					β+?	105Cd
106In	49	57	105.9134636(13)	6.2(1) min	β+	106Cd	7+
106mIn	28.6(3) keV			5.2(1) min	β+	106Cd	(2)+
107In	49	58	106.910287(10)	32.4(3) min	β+	107Cd	9/2+
107mIn	678.5(3) keV			50.4(6) s	IT	107In	1/2−
108In	49	59	107.9096937(93)	58.0(12) min	β+	108Cd	7+
108mIn	29.75(5) keV			39.6(7) min	β+	108Cd	2+
109In	49	60	108.9071497(43)	4.159(10) h	β+	109Cd	9/2+
109m1In	649.79(10) keV			1.34(6) min	IT	109In	1/2−
109m2In	2101.86(11) keV			210.0(9) ms	IT	109In	19/2+
110In	49	61	109.907171(12)	4.92(8) h	β+	110Cd	7+
110mIn	62.08(4) keV			69.1(5) min	β+	110Cd	2+
111In[n 10]	49	62	110.9051072(37)	2.8048(1) d	EC	111Cd	9/2+
111mIn	536.99(7) keV			7.7(2) min	IT	111In	1/2−
112In	49	63	111.9055387(46)	14.88(15) min	β+ (62%)	112Cd	1+
					β− (38%)	112Sn
112m1In	156.592(25) keV			20.67(8) min	IT	112In	4+
112m2In	350.80(5) keV			690(50) ns	IT	112In	(7)+
112m3In	613.82(6) keV			2.81(3) μs	IT	112In	8−
113In[n 11]	49	64	112.90406045(20)	Stable			9/2+	0.04281(52)
113mIn	391.699(3) keV			1.6579(4) h	IT	113In	1/2−
114In	49	65	113.90491641(32)	71.9(1) s	β− (99.50%)	114Sn	1+
					β+ (0.50%)	114Cd
114m1In	190.2682(8) keV			49.51(1) d	IT (96.75%)	114In	5+
					β+ (3.25%)	114Cd
114m2In	501.948(3) keV			43.1(6) ms	IT	114m1In	8−
115In[n 11][n 12]	49	66	114.903878772(12)	4.41(25)×1014 y	β−	115Sn	9/2+	0.95719(52)
115mIn[n 11]	336.244(17) keV			4.486(4) h	IT (95.0%)	115In	1/2−
					β− (5.0%)	115Sn
116In	49	67	115.90525999(24)	14.10(3) s	β− (99.98%)	116Sn	1+
					EC (0.0237%)	116Cd
116m1In	127.267(6) keV			54.29(17) min	β−	116Sn	5+
116m2In	289.660(6) keV			2.18(4) s	IT	116m1In	8−
117In	49	68	116.9045157(52)	43.2(3) min	β−	117Sn	9/2+
117mIn	315.303(11) keV			116.2(3) min	β− (52.9%)	117Sn	1/2−
					IT (47.1%)	117In
118In	49	69	117.9063567(83)	5.0(5) s	β−	118Sn	1+
118m1In[n 9]	100(50)# keV			4.364(7) min	β−	118Sn	5+
118m2In	240(50)# keV			8.5(3) s	IT (98.6%)	118m1In	8−
					β− (1.4%)	118Sn
119In	49	70	118.9058516(78)	2.4(1) min	β−	119Sn	9/2+
119m1In	311.37(3) keV			18.0(3) min	β− (97.4%)	119Sn	1/2−
					IT (2.6%)	119In
119m2In	654.27(7) keV			130(15) ns	IT	119In	(3/2)+
119m3In	2656.9(18) keV			265(10) ns	IT	119In	(25/2+)
120In	49	71	119.9079875(33)[7]	3.08(8) s	β−	120Sn	1+
120m1In	90.1(26) keV[7]			46.2(8) s	β−	120Sn	5+
120m2In[n 13]	90.1(26) keV[7]			47.3(5) s	β−	120Sn	8−
121In	49	72	120.9078416(13)[7]	23.1(6) s	β−	121Sn	9/2+
121m1In	313.68(7) keV			3.88(10) min	β− (98.8%)	121Sn	1/2−
					IT (1.2%)	121In
121m2In	2550(100)# keV			7.3(2) μs	IT	121In	(25/2+)
122In	49	73	121.9103046(13)[7]	10.3(6) s	β−	122Sn	5+
122m1In[n 9]	<15 keV[7]			10.8(4) s	β−	122Sn	8−
122m2In	77.2(15) keV[7]			1.5(3) s	β−	122Sn	1+
123In	49	74	122.9104679(12)[7]	6.17(5) s	β−	123mSn	9/2+
123m1In	327.21(4) keV			47.4(4) s	β−	123Sn	1/2−
123m2In	2078.1(6) keV			1.4(2) μs	IT	123In	(17/2−)
123m3In	2103(14)# keV			>100 μs	IT	123In	(21/2−)
124In	49	75	123.9131390(34)[7]	3.67(03) s	β−	124Sn	8−
124mIn	24.2(26) keV[7]			3.12(9) s	β−	124Sn	3+
125In	49	76	124.9136738(19)	2.36(4) s	β−	125mSn	9/2+
125m1In	352(12) keV			12.2(2) s	β−	125Sn	1/2−
125m2In	2009.4(7) keV			9.4(6) μs	IT	125In	(19/2+)
125m3In	2161.2(9) keV			5.0(15) ms	IT	125In	(23/2−)
126In	49	77	125.9164682(45)	1.53(1) s	β−	126Sn	3+
126m1In	90(7) keV			1.64(5) s	β−	126Sn	8−
126m2In	243.3(2) keV			22(2) μs	IT	126In	1−
127In	49	78	126.9174539(14)[8]	1.086(7) s	β− (>99.97%)	127mSn	9/2+
					β−, n (<0.03%)	126Sn
127m1In	407.9(50) keV[8]			3.618(21) s	β− (99.30%)	127mSn	1/2−#
					β−, n (0.70%)	126Sn
127m2In	1728.7(12) keV[8]			1.04(10) s	β−	127mSn	(21/2−)
					β−, n?	126Sn
127m3In	2364.7(9) keV			9(2) μs	IT	127In	(29/2+)
128In	49	79	127.9203536(14)	816(27) ms	β− (99.96%)	128Sn	(3)+
					β−, n (0.038%)	127Sn
128m1In	247.87(10) keV			23(2) μs	IT	128In	(1)−
128m2In	285.1(22) keV			720(100) ms	β−	128Sn	(8−)
					IT?	128In
					β−, n?	127Sn
128m3In	1797.6(16) keV			>0.3 s	β−	128Sn	(16+)
					IT?	128In
					β−, n?	127Sn
129In	49	80	128.9218085(21)	570(10) ms	β− (99.77%)	129Sn	9/2+
					β−, n (0.23%)	128Sn
129m1In	449.1(59) keV[8]			1.23(3) s	β− (96.2%)	129Sn	1/2−
					β−, n (3.6%)	128Sn
					IT?	129In
129m2In	1646.6(33) keV[8]			670(100) ms	β−	129Sn	(23/2−)
					IT?	129In
129m3In	1687.97(25) keV			11.2(2) μs	IT	129In	(17/2−)
129m4In	1927.6(33) keV[8]			110(15) ms	IT	129In	(29/2+)
					β−?	129Sn
130In	49	81	129.9249523(19)	273(5) ms	β− (99.07%)	130Sn	1(−)
					β−, n (0.93%)	129Sn
130m1In[n 9]	66.5(27) keV			540(10) ms	β− (98.20%)	130Sn	(10-)
					β−, n (1.80%)	129Sn
130m2In	385.4(26) keV			540(10) ms	β− (98.20%)	130Sn	(5+)
					β−, n (1.80%)	129Sn
130m3In	388.3(2) keV			4.6(2) μs	IT	130In	(3+)
131In	49	82	130.9269728(24)	261.5(28) ms	β− (97.75%)	131Sn	9/2+
					β−, n (2.25%)	130Sn
131m1In	376(3) keV			328(15) ms	β− (97.75%)	131Sn	1/2−
					β−, n (2.25%)	130Sn
					IT?	131In
131m2In	3750(90) keV			322(41) ms	β− (88%)	131Sn	(21/2+)
					β−, n (12%)	130Sn
					IT?	129Sn
131m3In	3783.6(5) keV			669(34) ns	IT	131In	(17/2+)
132In	49	83	131.932998(64)	202.2(2) ms	β− (87.7%)	132Sn	(7−)
					β−, n (12.3%)	131Sn
					β−, 2n?	130Sn
133In	49	84	132.93807(22)#	163.0(16) ms	β−, n (85%)	132Sn	(9/2+)
					β− (15%)	133Sn
					β−, 2n?	131Sn
133mIn	330(40)# keV			167(11) ms	β−, n (93%)	132Sn	(1/2−)
					β− (7%)	133Sn
134In	49	85	133.94421(22)#	140(4) ms	β−, n (65%)	133Sn	7−#
					β−?	134Sn
					β−, 2n (<4%)	132Sn
134mIn	56.7(1) keV			3.5(4) μs	IT	134In	(5−)
135In	49	86	134.94943(32)#	103(3) ms	β−	135Sn	9/2+#
					β−, n?	134Sn
					β−, 2n?	133Sn
136In	49	87	135.95602(32)#	86(9) ms	β−	136Sn	7−#
					β−, n?	135Sn
					β−, 2n?	134Sn
137In	49	88	136.96154(43)#	70(40) ms	β−	137Sn	9/2+#
					β−, n?	136Sn
					β−, 2n?	135Sn
This table header & footer: view

1. ^mIn – Excited nuclear isomer.
2. ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
3. # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
4. # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
5. Modes of decay:

   EC:	Electron capture
   IT:	Isomeric transition
   n:	Neutron emission
   p:	Proton emission

6. Bold italics symbol as daughter – Daughter product is nearly stable.
7. Bold symbol as daughter – Daughter product is stable.
8. ( ) spin value – Indicates spin with weak assignment arguments.
9. Order of ground state and isomer is uncertain.
10. Used in medical applications
11. Fission product
12. Primordial radionuclide
13. Order of isomers is uncertain.

See also

Daughter products other than indium

• Isotopes of tin
• Isotopes of cadmium
• Isotopes of silver