Isotopes of platinum

Natural platinum (Pt) occurs in five stable isotopes (192Pt, 194Pt, 195Pt, 196Pt, 198Pt) and one very-long lived (half-life 6.50×1011 years) radioisotope (190Pt). There are also 31 known artificial radioisotopes, the longest-lived of which is 193Pt with a half-life of 50 years. All other isotopes have half-lives under a year, most under a day.

Standard atomic mass: 195.084(9) u

Table

nuclide
symbol
Z(p) N(n)  
isotopic mass (u)
 
half-life[n 1] decay
mode(s)[1][n 2]
daughter
isotope(s)[n 3]
nuclear
spin
representative
isotopic
composition
(mole fraction)
range of natural
variation
(mole fraction)
excitation energy
166Pt 78 88 165.99486(54)# 300(100) µs 0+
167Pt 78 89 166.99298(44)# 700(200) µs 7/2-#
168Pt 78 90 167.98815(22) 2.00(18) ms α 164Os 0+
β+ (rare) 168Ir
169Pt 78 91 168.98672(22)# 3.7(15) ms α 165Os 3/2-#
β+ (rare) 169Ir
170Pt 78 92 169.982495(20) 14.0(2) ms α (98%) 166Os 0+
β+ (2%) 170Ir
171Pt 78 93 170.98124(9) 51(2) ms α (99%) 167Os 3/2-#
β+ (1%) 171Ir
172Pt 78 94 171.977347(14) 98.4(24) ms α (77%) 168Os 0+
β+ (23%) 172Ir
173Pt 78 95 172.97644(6) 365(7) ms α (84%) 169Os 5/2-#
β+ (16%) 173Ir
174Pt 78 96 173.972819(13) 0.889(17) s α (83%) 170Os 0+
β+ (17%) 174Ir
175Pt 78 97 174.972421(20) 2.53(6) s α (64%) 171Os 5/2-#
β+ (36%) 175Ir
176Pt 78 98 175.968945(15) 6.33(15) s β+ (62%) 176Ir 0+
α (38%) 172Os
177Pt 78 99 176.968469(16) 10.6(4) s β+ (94.4%) 177Ir 5/2-
α (5.6%) 173Os
177mPt 147.4(4) keV 2.2(3) µs 1/2-
178Pt 78 100 177.965649(12) 21.1(6) s β+ (92.3%) 178Ir 0+
α (7.7%) 174Os
179Pt 78 101 178.965363(10) 21.2(4) s β+ (99.76%) 179Ir 1/2-
α (0.24%) 175Os
180Pt 78 102 179.963031(12) 56(2) s β+ (99.7%) 180Ir 0+
α (0.3%) 176Os
181Pt 78 103 180.963097(16) 52.0(22) s β+ (99.93%) 181Ir 1/2-
α (0.074%) 177Os
182Pt 78 104 181.961171(17) 2.2(1) min β+ (99.96%) 182Ir 0+
α (.038%) 178Os
183Pt 78 105 182.961597(17) 6.5(10) min β+ (99.99%) 183Ir 1/2-
α (.0096%) 179Os
183m1Pt 34.50(8) keV 43(5) s β+ (99.99%) 183Ir (7/2)-
α (4×10−4%) 179Os
IT 183Pt
183m2Pt 195.68(11) keV >150 ns (9/2)+
184Pt 78 106 183.959922(19) 17.3(2) min β+ (99.99%) 184Ir 0+
α (.00169%) 180Os
184mPt 1839.4(16) keV 1.01(5) ms IT 184Pt 8-
185Pt 78 107 184.96062(4) 70.9(24) min β+ (99.99%) 185Ir (9/2+)
α (.005%) 181Os
185mPt 103.4(2) keV 33.0(8) min β+ (98%) 185Ir (1/2-)
α (2%) 181Os
186Pt 78 108 185.959351(23) 2.08(5) h β+ (99.99%) 186Ir 0+
α (1.4×10−4%) 182Os
187Pt 78 109 186.96059(3) 2.35(3) h β+ 187Ir 3/2-
188Pt 78 110 187.959395(6) 10.2(3) d EC (99.99%) 188Ir 0+
α (2.6×10−5%) 184Os
189Pt 78 111 188.960834(12) 10.87(12) h β+ 189Ir 3/2-
189m1Pt 172.80(6) keV 464(25) ns 9/2-
189m2Pt 191.6(4) keV 143(5) µs (13/2+)
190Pt 78 112 189.959932(6) 6.5(3)×1011 a α 186Os 0+ 1.4(1)×10−4
191Pt 78 113 190.961677(5) 2.862(7) d EC 191Ir 3/2-
191m1Pt 100.67(2) keV >1 µs (9/2)-
191m2Pt 149.04(2) keV 95(5) µs (13/2)+
192Pt 78 114 191.9610380(27) Observationally Stable[n 4] 0+ 0.00782(7)
193Pt 78 115 192.9629874(18) 50(6) a EC 193Ir 1/2-
193mPt 149.78(4) keV 4.33(3) d IT 193Pt 13/2+
194Pt 78 116 193.9626803(9) Observationally Stable[n 5] 0+ 0.32967(99)
195Pt 78 117 194.9647911(9) Observationally Stable[n 6] 1/2- 0.33832(10)
195mPt 259.30(8) keV 4.010(5) d IT 195Pt 13/2+
196Pt 78 118 195.9649515(9) Observationally Stable[n 7] 0+ 0.25242(41)
197Pt 78 119 196.9673402(9) 19.8915(19) h β 197Au 1/2-
197mPt 399.59(20) keV 95.41(18) min IT (96.7%) 197Pt 13/2+
β (3.3%) 197Au
198Pt 78 120 197.967893(3) Observationally Stable[n 8] 0+ 0.07163(55)
199Pt 78 121 198.970593(3) 30.80(21) min β 199Au 5/2-
199mPt 424(2) keV 13.6(4) s IT 199Pt (13/2)+
200Pt 78 122 199.971441(22) 12.5(3) h β 200Au 0+
201Pt 78 123 200.97451(5) 2.5(1) min β 201Au (5/2-)
202Pt 78 124 201.97574(32)# 44(15) h β 202Au 0+
  1. Bold for isotopes with half-lives longer than the age of the universe (nearly stable)
  2. Abbreviations:
    EC: Electron capture
    IT: Isomeric transition
  3. Bold for stable isotopes, bold italics for nearly-stable isotopes (half-life longer than the age of the universe)
  4. Believed to undergo α decay to 188Os with a half-life over 470×1015 years
  5. Believed to undergo α decay to 190Os
  6. Believed to undergo α decay to 191Os
  7. Believed to undergo α decay to 192Os
  8. Believed to undergo α decay to 194Os or double β decay to 198Hg with a half-life over 320×1012 years

Notes

References

  1. http://www.nucleonica.net/unc.aspx
Isotopes of iridium Isotopes of platinum Isotopes of gold
Table of nuclides