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Talk:Refractory metals

Latest comment: 8 years ago by Double sharp in topic Why no Os?

Chemistry topics

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If this could be promoted to GA, we'd have another chemistry good/featured topic! Lanthanum-138 (talk) 02:39, 9 May 2011 (UTC)Reply

Why no Os?

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Is there a reason Osmium is excluded from this group in most definitions? Its melting point is 3306K, higher than those of Nb, Ta, and Mo, and exceeded only by W and Re. Does it have anything to do with osmium tetroxide being volatile (and therefore unsafe)? Difluoroethene (talk) 18:59, 18 September 2011 (UTC)Reply

Some authors include it, but I imagine this is a significant issue with Os, since the reaction to form OsO4 happens gradually at ambient temperature: that's how it got its name, after all! Also, if Ti makes the cut, then so should Pt with a melting point of 2041 K. I can understand Th (melting point 2115 K) being snubbed for its radioactivity, but we're not even consistent with our 2123 K criterion (which would list Zr, Cr, V, Rh, [Tc], Hf, Ru, Ir, Nb, Mo, Ta, Os, Re, and W, but not Ti). (For the 2000 °C list, start at [Tc]; for the 2200 °C list, start at Hf.) Double sharp (talk) 16:57, 18 June 2016 (UTC)Reply