Isotopes of platinum

Naturally occurring platinum (₇₈Pt) consists of five stable isotopes (¹⁹²Pt, ¹⁹⁴Pt, ¹⁹⁵Pt, ¹⁹⁶Pt, ¹⁹⁸Pt) and one very long-lived (half-life 4.83×10¹¹ years) radioisotope (¹⁹⁰Pt). There are also 34 known synthetic 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. All isotopes of platinum are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed. Platinum-195 is the most abundant isotope.

Isotopes of platinum (₇₈Pt)

Main isotopes^[1] Decay abun­dance half-life (t1/2) mode pro­duct ^190Pt 0.0120% 4.83×10^11 y α ^186Os ^192Pt 0.782% stable ^193Pt synth 50 y ε ^193Ir ^194Pt 32.9% stable ^195Pt 33.8% stable ^196Pt 25.2% stable ^198Pt 7.36% stable
Standard atomic weight Ar°(Pt)
	195.084±0.009^[2] 195.08±0.02 (abridged)^[3]
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List of isotopes

Nuclide ^[n 1]	Z	N	Isotopic mass (Da)^[4] ^[n 2]^[n 3]	Half-life^[1] ^[n 4]	Decay mode^[1] ^[n 5]	Daughter isotope ^[n 6]^[n 7]	Spin and parity^[1] ^[n 8]^[n 9]	Natural abundance (mole fraction)
	Excitation energy^[n 9]							Normal proportion^[1]	Range of variation
^165Pt	78	87	164.99966(43)#	370(180) μs	α	^161Os	7/2−#
^166Pt	78	88	165.99487(32)#	294(62) μs	α	^162Os	0+
^167Pt	78	89	166.99275(33)#	920(120) μs	α	^163Os	7/2−#
^168Pt	78	90	167.98818(16)	2.02(10) ms	α	^164Os	0+
					β^+ ?	^168Ir
^169Pt	78	91	168.98662(22)#	6.99(9) ms	α	^165Os	(7/2−)
					β^+ ?	^169Ir
^170Pt	78	92	169.982502(20)	13.93(16) ms	α	^166Os	0+
					β^+ ?	^170Ir
^171Pt	78	93	170.981249(87)	45.5(25) ms	α (86%)	^167Os	7/2−
					β^+ (14%)	^171Ir
^171mPt	412.6(10) keV			901(9) ns	IT	^171Pt	13/2+
^172Pt	78	94	171.977341(11)	97.6(13) ms	α (96%)	^168Os	0+
					β^+ (4%)	^172Ir
^173Pt	78	95	172.976450(68)	382(2) ms	α (86%)	^169Os	(5/2−)
					β^+ (14%)	^173Ir
^174Pt	78	96	173.972820(11)	862(8) ms	α (74.9%)	^170Os	0+
					β^+ (25.1%)	^174Ir
^175Pt	78	97	174.972401(20)	2.43(4) s	α (64%)	^171Os	(7/2−)
					β^+ (36%)	^175Ir
^176Pt	78	98	175.968938(14)	6.33(15) s	β^+ (60%)	^176Ir	0+
					α (40%)	^172Os
^177Pt	78	99	176.968470(16)	10.0(04) s	β^+ (94.3%)	^177Ir	5/2−
					α (5.7%)	^173Os
^177mPt	147.5(4) keV			2.35(4) μs	IT	^177Pt	1/2−
^178Pt	78	100	177.965649(11)	20.7(7) s	β^+ (92.3%)	^178Ir	0+
					α (7.7%)	^174Os
^179Pt	78	101	178.9653588(86)	21.2(4) s	β^+ (99.76%)	^179Ir	1/2−
					α (0.24%)	^175Os
^180Pt	78	102	179.963038(11)	56(3) s	β^+ (99.48%)	^180Ir	0+
					α (0.52%)	^176Os
^181Pt	78	103	180.963090(15)	52.0(22) s	β^+ (99.93%)	^181Ir	1/2−
					α (0.074%)	^177Os
^181mPt	116.65(8) keV			>300 ns	IT	^181Pt	7/2−
^182Pt	78	104	181.961172(14)	2.67(12) min	β^+ (99.962%)	^182Ir	0+
					α (0.038%)	^178Os
^183Pt	78	105	182.961596(15)	6.5(10) min	β^+ (99.99%)	^183Ir	1/2−
					α (0.0096%)	^179Os
^183m1Pt	34.74(7) keV			43(5) s	β^+ (96.9%)	^183Ir	7/2−
					IT (3.1%)	^183Pt
					α ?	^179Os
^183m2Pt	195.90(10) keV			>150 ns	IT	^183Pt	9/2+
^184Pt	78	106	183.959922(16)	17.3(2) min	β^+	^184Ir	0+
					α (0.0017%)	^180Os
^184mPt	1840.3(8) keV			1.01(5) ms	IT	^184Pt	8−
^185Pt	78	107	184.960614(28)	70.9(24) min	β^+	^185Ir	9/2+
					α (0.0050%)	^181Os
^185m1Pt	103.41(5) keV			33.0(8) min	β^+	^185Ir	1/2−
^185m2Pt	200.89(4) keV			728(20) ns	IT	^185Pt	5/2−
^186Pt	78	108	185.959351(23)	2.08(5) h	β^+	^186Ir	0+
					α (1.4×10^−4%)	^182Os
^187Pt	78	109	186.960617(26)	2.35(3) h	β^+	^187Ir	3/2−
^187mPt	174.38(22) keV			311(15) μs	IT	^187Pt	11/2+
^188Pt	78	110	187.9593975(57)	10.16(18) d	EC	^188Ir	0+
					α (2.6×10^−5%)	^184Os
^189Pt	78	111	188.960848(11)	10.87(12) h	β^+	^189Ir	3/2−
^189m1Pt	172.79(6) keV			464(25) ns	IT	^189Pt	9/2−
^189m2Pt	191.6(4) keV			143(5) μs	IT	^189Pt	(13/2+)
^190Pt	78	112	189.95994982(71)	4.83(3)×10^11 y	α^[n 10]	^186Os	0+	1.2(2)×10^−4
^191Pt	78	113	190.9616763(44)	2.83(2) d	EC	^191Ir	3/2−
^191m1Pt	100.663(20) keV			>1 μs	IT	^191Pt	9/2−
^191m2Pt	149.035(22) keV			95(5) μs	IT	^191Pt	13/2+
^192Pt	78	114	191.9610427(28)	Observationally Stable^[n 11]			0+	0.00782(24)
^192mPt	2172.37(13) keV			272(23) ns	IT	^192Pt	10−
^193Pt	78	115	192.9629845(15)	50(6) y	EC	^193Ir	1/2−
^193mPt	149.78(4) keV			4.33(3) d	IT	^193Pt	13/2+
^194Pt	78	116	193.96268350(53)	Observationally Stable^[n 12]			0+	0.3286(41)
^195Pt	78	117	194.96479433(54)	Observationally Stable^[n 13]			1/2−	0.3378(24)
^195mPt	259.077(23) keV			4.010(5) d	IT	^195Pt	13/2+
^196Pt	78	118	195.96495465(55)	Observationally Stable^[n 14]			0+	0.2521(34)
^197Pt	78	119	196.96734303(58)	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	197.9678967(23)	Observationally Stable^[n 15]			0+	0.0734(13)
^199Pt	78	121	198.9705970(23)	30.80(21) min	β^−	^199Au	5/2−
^199mPt	424(2) keV			13.48(16) s	IT	^199Pt	13/2+
^200Pt	78	122	199.971445(22)	12.6(3) h	β^−	^200Au	0+
^201Pt	78	123	200.974513(54)	2.5(1) min	β^−	^201Au	(5/2−)
^202Pt	78	124	201.975639(27)	44(15) h	β^−	^202Au	0+
^202mPt	1788.5(4) keV			141(7) μs	IT	^202Pt	(7−)
^203Pt	78	125	202.97906(22)#	22(4) s	β^−	^203Au	(1/2−)
^203m1Pt	1367(3)# keV			12(5) s	β^−	^203Au	13/2+#
					IT ?	^203Pt
^203m2Pt	1420(50)# keV			>100# ns	IT	^203Pt	27/2−#
^203m3Pt	2530(50)# keV			641(55) ns	IT	^203Pt	33/2+#
^204Pt	78	126	203.98108(22)#	10.3(14) s	β^−	^204Au	0+
^204m1Pt	1995.1(07) keV			5.5(7) μs	IT	^204Pt	(5−)
^204m2Pt	2035(23) keV			55(3) μs	IT	^204Pt	(7−)
^204m3Pt	3193(23) keV			146(14) ns	IT	^204Pt	(10+)
^205Pt	78	127	204.98624(32)#	2# s	β^− ?	^205Au	9/2+#
^206Pt	78	128	205.99008(32)#	500# ms	β^− ?	^206Au	0+
					β^−n ?	^205Au
^207Pt	78	129	206.99556(43)#	600# ms	β^− ?	^207Au	9/2+#
					β^−n ?	^206Au
^208Pt	78	130	207.99946(43)#	220# ms	β^− ?	^208Au	0+
					β^−n ?	^207Au
This table header & footer: view

1. ^mPt – 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. Bold half-life – nearly stable, half-life longer than age of universe.
5. Modes of decay:

   EC:	Electron capture
   IT:	Isomeric transition

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. # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
10. Theorized to also undergo β⁺β⁺ decay to ¹⁹⁰Os
11. Believed to undergo α decay to ¹⁸⁸Os with a half-life over 6.0×10¹⁶ years
12. Believed to undergo α decay to ¹⁹⁰Os
13. Believed to undergo α decay to ¹⁹¹Os with a half-life over 6.3×10¹⁸ years
14. Believed to undergo α decay to ¹⁹²Os
15. Believed to undergo α decay to ¹⁹⁴Os or double β⁻ decay to ¹⁹⁸Hg with a half-life over 3.20×10¹⁴ years

References

1. Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
2. "Standard Atomic Weights: Platinum". CIAAW. 2005.
3. Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
4. Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.

• Isotope masses from:
  • Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
• Isotopic compositions and standard atomic masses from:
  • de Laeter, John Robert; Böhlke, John Karl; De Bièvre, Paul; Hidaka, Hiroshi; Peiser, H. Steffen; Rosman, Kevin J. R.; Taylor, Philip D. P. (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry. 75 (6): 683–800. doi:10.1351/pac200375060683.
  • Wieser, Michael E. (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry. 78 (11): 2051–2066. doi:10.1351/pac200678112051.
• "News & Notices: Standard Atomic Weights Revised". International Union of Pure and Applied Chemistry. 19 October 2005.
• Half-life, spin, and isomer data selected from the following sources.
  • Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
  • National Nuclear Data Center. "NuDat 2.x database". Brookhaven National Laboratory.
  • Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.