Talk:Refractory metals
 | A fact from Refractory metals appeared on Wikipedia's Main Page in the Did you know column on 3 April 2004. The text of the entry was as follows:
|  |
 | This article is rated B-class on Wikipedia's content assessment scale. It is of interest to the following WikiProjects: | ||||||||||
| |||||||||||
|
|
|
This page has archives. Sections older than 730 days may be automatically archived by Lowercase sigmabot III when more than 2 sections are present. |
Why no Os?
[edit]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)
- 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)
Carbon
[edit]I'd also add that carbon's melting point is >2 000 degrees Celsius. Boron also has a melting point above 1850 degrees Celsius. Carbon is higher than tungsten. The 5 refractory metals have higher melting points than iridium, 2 of which higher than osmium. 174.103.211.175 (talk) 19:43, 6 December 2024 (UTC)
- Carbon doesn't melt at standard conditions; it sublimes. Double sharp (talk) 13:46, 9 December 2024 (UTC)
- Carbon is solid up to higher temperatures, with a melting/sublimation point >2 000 degrees Celsius. 174.103.211.175 (talk) 02:29, 16 December 2024 (UTC)