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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.

Main isotopes of indium (49In)
Iso­tope Decay
abun­dance half-life (t1/2) mode pro­duct
111In syn 2.8 d ε 111Cd
113In 4.28% stable
115In 95.72% 4.41×1014 y β 115Sn
Standard atomic weight Ar, standard(In)

The stable isotope 113In is only 4.3% of naturally occurring indium. Among elements with a known stable isotope, only tellurium and rhenium similarly occur with a stable isotope in lower abundance than the long-lived radioactive isotope. Other than 115In, the longest-lived radioisotope is 111In, with a half-life of 2.8047 days. All other radioisotopes have half-lives less than a day. 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 less than a day, most less than an hour, and many measured in milliseconds or less.

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).[2] Indium-111 is also used in indium white blood cell scans, which use nuclear medical techniques to search for hidden infections.

List of isotopesEdit

Nuclide
[n 1]
Z N Isotopic mass (u)
[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
97In 49 48 96.94954(64)# 5# ms 9/2+#
98In 49 49 97.94214(21)# 45(23) ms
[32(+32−11) ms]
β+ 98Cd 0+#
98mIn 0(500)# keV 1.7(8) s
[1.2(+12−4) s]
99In 49 50 98.93422(43)# 3.1(8) s
[3.0(+8-7) s]
β+ 99Cd 9/2+#
99mIn 400(150)# keV 1# s 1/2−#
100In 49 51 99.93111(27) 5.9(2) s β+ (96.1%) 100Cd (6, 7)+
β+, p (3.9%) 99Ag
101In 49 52 100.92634(32)# 15.1(3) s β+ 100Cd 9/2+#
β+, p 100Ag
101mIn 550(100)# keV 10# s 1/2−#
102In 49 53 101.92409(12) 23.3(1) s β+ (99.99%) 102Cd (6+)
β+, p (.00929%) 101Ag
103In 49 54 102.919914(27) 60(1) s β+ 103Cd 9/2+#
103mIn 631.7(1) keV 34(2) s (1/2−)#
104In 49 55 103.91830(9) 1.80(3) min β+ 104Cd 5, 6(+)
104mIn 93.48(10) keV 15.7(5) s IT (80%) 104In (3+)
β+ (20%) 104Cd
105In 49 56 104.914674(19) 5.07(7) min β+ 105Cd 9/2+
105mIn 674.1(3) keV 48(6) s IT 105In (1/2)−
106In 49 57 105.913465(13) 6.2(1) min β+ 106Cd 7+
106mIn 28.6(3) keV 5.2(1) min β+ 106Cd (3+)
107In 49 58 106.910295(12) 32.4(3) min β+ 107Cd 9/2+
107mIn 678.5(3) keV 50.4(6) s IT 107In 1/2−
108In 49 59 107.909698(10) 58.0(12) min β+ 108Cd 7+
108mIn 29.75(5) keV 39.6(7) min β+ 108Cd 2+
109In 49 60 108.907151(6) 4.2(1) h β+ 109Cd 9/2+
109m1In 650.1(3) keV 1.34(7) min IT 109In 1/2−
109m2In 2101.8(2) keV 209(6) ms (19/2+)
110In 49 61 109.907165(13) 4.9(1) h β+ 110Cd 7+
110mIn 62.1(5) keV 69.1(5) min β+ 110Cd 2+
111In[n 9] 49 62 110.905103(5) 2.8047(5) d EC 111Cd 9/2+
111mIn 536.95(6) keV 7.7(2) min IT 111In 1/2−
112In 49 63 111.905532(6) 14.97(10) min β+ (56%) 112Cd 1+
β (44%) 112Sn
112m1In 156.59(5) keV 20.56(6) min β+ 112Cd 4+
112m2In 350.76(9) keV 690(50) ns 7+
112m3In 613.69(14) keV 2.81(3) μs 8-
113In 49 64 112.904058(3) Stable 9/2+ 0.0429(5)
113mIn 391.699(3) keV 1.6579(4) h IT 113In 1/2−
114In 49 65 113.904914(3) 71.9(1) s β+ (0.5%) 114Cd 1+
β (99.5%) 114Sn
114m1In 190.29(3) keV 49.51(1) d IT (96.75%) 114In 5+
β+ (3.25%) 114Cd
114m2In 501.94(3) keV 43.1(6) ms IT (96.75%) 114In (8−)
β+ (3.25%) 114Cd
114m3In 641.72(3) keV 4.3(4) μs (7+)
115In[n 10][n 11] 49 66 114.903878(5) 4.41(25)×1014 a β 115Sn 9/2+ 0.9571(5)
115mIn 336.244(17) keV 4.486(4) h IT (95%) 115In 1/2−
β (5%) 115Sn
116In 49 67 115.905260(5) 14.10(3) s β 116Sn 1+
EC 116Cd
116m1In 127.267(6) keV 54.29(17) min 5+
116m2In 289.660(6) keV 2.18(4) s 8-
117In 49 68 116.904514(6) 43.2(3) min β 117Sn 9/2+
117mIn 315.302(12) keV 116.2(3) min β (52.91%) 117Sn 1/2−
IT (47.09%) 117In
118In 49 69 117.906354(9) 5.0(5) s β 118Sn 1+
118m1In 100(50)# keV 4.364(7) min β 118Sn 5+
118m2In 240(50)# keV 8.5(3) s 8-
119In 49 70 118.905845(8) 2.4(1) min β 119Sn 9/2+
119m1In 311.37(3) keV 18.0(3) min β (94.4%) 119Sn 1/2−
IT (5.6%) 119In
119m2In 654.27(7) keV 130(15) ns 1/2+, 3/2+
120In 49 71 119.90796(4) 3.08(8) s β 120Sn 1+
120m1In 50(60)# keV 46.2(8) s 5+
120m2In 300(200)# keV 47.3(5) s β 120Sn 8(−)
121In 49 72 120.907846(29) 23.1(6) s β 121Sn 9/2+
121mIn 312.98(8) keV 3.88(10) min β (98.8%) 121Sn 1/2−
IT (1.2%) 121In
122In 49 73 121.91028(5) 1.5(3) s β 122Sn 1+
122m1In 40(60)# keV 10.3(6) s 5+
122m2In 290(140) keV 10.8(4) s β 122Sn 8-
123In 49 74 122.910438(26) 6.17(5) s β 123mSn (9/2)+
123mIn 327.21(4) keV 47.4(4) s β 123mSn (1/2)−
124In 49 75 123.91318(5) 3.11(10) s β 124Sn 3+
124mIn -20(70) keV 3.7(2) s β 124Sn (8)(−#)
IT 124In
125In 49 76 124.91360(3) 2.36(4) s β 125mSn 9/2+
125mIn 360.12(9) keV 12.2(2) s β 125Sn 1/2(−)
126In 49 77 125.91646(4) 1.53(1) s β 126Sn 3(+#)
126mIn 100(60) keV 1.64(5) s β 126Sn 8(−#)
127In 49 78 126.91735(4) 1.09(1) s β (99.97%) 127mSn 9/2(+)
β, n (.03%) 126Sn
127mIn 460(70) keV 3.67(4) s β (99.31%) 127mSn (1/2−)
β, n (.69%) 126Sn
128In 49 79 127.92017(5) 0.84(6) s β (99.96%) 128Sn (3)+
β, n (.038%) 127Sn
128m1In 247.87(10) keV 10(7) ms (1)−
128m2In 320(60) keV 720(100) ms β 128Sn (8−)
129In 49 80 128.92170(5) 611(4) ms β (99.75%) 129Sn 9/2+#
β, n (.25%) 128Sn
129m1In 380(70) keV 1.23(3) s β (97.2%) 129Sn (1/2−)#
β, n (2.5%) 128Sn
IT (.3%) 129In
129m2In 1688.0(5) keV 8.5(5) μs 17/2−
130In 49 81 129.92497(4) 0.29(2) s β (98.35%) 130Sn 1(−)
β, n (1.65%) 129Sn
130m1In 50(50) keV 538(5) ms 10-#
130m2In 400(60) keV 0.54(1) s (5+)
131In 49 82 130.92685(3) 0.28(3) s β (97.8%) 131Sn (9/2+)
β, n (2.19%) 130Sn
131m1In 363(37) keV 0.35(5) s (1/2−)
131m2In 4.10(7) MeV 320(60) ms (19/2+ to 23/2+)
132In 49 83 131.93299(7) 206(4) ms β (94.8%) 132Sn (7−)
β, n (5.2%) 131Sn
133In 49 84 132.93781(32)# 165(3) ms β, n (85%) 132Sn (9/2+)
β (15%) 133Sn
133mIn 330(40)# keV 180# ms IT 133In (1/2−)
134In 49 85 133.94415(43)# 140(4) ms β (79%) 134Sn
β, n (17%) 133Sn
β, 2n (4%) 132Sn
135In 49 86 134.94933(54)# 92(10) ms β 135Sn 9/2+#
136In 49 87 85 ms β 136Sn
137In 49 88 65 ms β 137Sn
  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. ^ a b c # – 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. ^ Used in medical applications
  10. ^ Fission product
  11. ^ Primordial radionuclide

ReferencesEdit

  1. ^ Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.
  2. ^ "Octreoscan review". Medscape.