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Platinum Metals Rev., 2012, 56, (4), 271
doi: 10.1595/147106712X654899

The Discoverers of the Isotopes of the Platinum Group of Elements: An Update

New discoveries in 2011 increase total number of known isotopes

  • John W. Arblaster
  • Wombourne, West Midlands, UK
  • Email:

Since the previous update on new isotopes of the platinum group of elements (1), further isotopes have been discovered and reported by Kurcewicz et al. (2) in 2011. These are: 202Os, 203Os, 204Ir, 205Ir and 206Pt to 209Pt. The discovery of the isotope 201Os was also claimed but this was previously identified by Kurtukian-Nieto (3) in 2007. All of these isotopes are particle stable (resistant to proton and neutron decay) and are likely to be β emitters. These discoveries bring the total number of known isotopes for the platinum group of elements as shown in Table I.

Table I

Total Number of Isotopes and Mass Ranges Known for Each Platinum Group Element to 2012

Element Number of known isotopes Known mass number ranges
Ruthenium 38 87–124
Rhodium 38 89–126
Palladium 38 91–128
Osmium 43 161–203
Iridium 42 164–205
Platinum 44 166–209


  1.  J. W. Arblaster, Platinum Metals Rev., 2011, 55, (4), 251 LINK
  2.  J. Kurcewicz, F. Farinon, H. Geissel, S. Pietri, C. Nociforo, A. Prochazka, H. Weick, J. S. Winfield, A. Estradé, P. R. P. Allegro, A. Bail, G. Bélier, J. Benlliure, G. Benzoni, M. Bunce, M. Bowry, R. Caballero-Folch, I. Dillmann, A. Evdokimov, J. Gerl, A. Gottardo, E. Gregor, R. Janik, A. Kelić-Heil, R. Knöbel, T. Kubo, Yu. A. Litvinov, E. Merchan, I. Mukha, F. Naqvi, M. Pfützner, M. Pomorski, Zs. Podolyák, P. H. Regan, B. Riese, M. V. Ricciardi, C. Scheidenberger, B. Sitar, P. Spiller, J. Stadlmann, P. Strmen, B. Sun, I. Szarka, J. Taïeb, S. Terashima, J. J. Valiente-Dobón, M. Winkler and Ph. Woods, eprint arXiv:1112.0521v1 [nucl-ex], 2nd December, 2011 LINK
  3.  T. Kurtukian-Nieto, ‘Production and β Decay Half-Lives of Heavy Neutron-Rich Nuclei Approaching the Stellar Nucleosynthesis R-Process Path Around A = 195’, PhD Thesis, University of Santiago De Compostela, Santiago De Compostela, Spain, 2007 LINK

The Author

John W. Arblaster is interested in the history of science and the evaluation of the thermodynamic and crystallographic properties of the elements. Now retired, he previously worked as a metallurgical chemist in a number of commercial laboratories and was involved in the analysis of a wide range of ferrous and non-ferrous alloys.

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