The article is adequately referenced, with reliable sources. Looks good.
It is broad in its coverage.
a (major aspects): b (focused):
The major aspects of the article are covered, including the chemical properties, discovery, applications, etc. I think it might be a good idea to move the 'occurrence' section up to fall immediately after 'characteristics' -- so the article would flow more naturally from a description of it's properties to its occurrence in nature or man-made activities.
Moved the occurrence section.--Stone (talk) 20:03, 14 June 2010 (UTC)
The 'history' section is usually the first section, immediately after the lead. In this case, it might be more accurate to change the title of that section to 'discovery' as well, since it really covers the discovery of the element.
Moved the history section and expanded it by the two mayor applications which were used in the early 2000s century in the 1920s and the 3-way converter in the mid 1970s.--Stone (talk) 20:03, 14 June 2010 (UTC)
The lead section is also too short, and doesn't really accurately summarize the article. For one, the applications section states that the primary use is in catalytic converters in automobiles, but this isn't even mentioned in the lead.
Expanded the lead with the applications.--Stone (talk) 20:03, 14 June 2010 (UTC)
The images are all tagged and captioned as appropriately required.
This article is in excellent shape! Save a few minor issues with criterion #3, I think this article meets the GA criteria. It can be promoted once the issues raised above are satisfied. I'll put it on hold until 6/23/2010, so that the issues can be resolved. WTF? (talk) 19:04, 9 June 2010 (UTC)
"Diluted nitric acid dissolved all but palladium and rhodium, which were dissolved in aqua regia" - History section in this article. "However, aqua regia does not dissolve or corrode titanium, iridium, ruthenium, rhenium, tantalum, niobium, hafnium, osmium, or rhodium"- Following link from Aqua regia article.
Tumorte (talk) 07:51, 7 August 2016 (UTC)Tumorte. 2016-08-07. 09:51.
Good point. Greenwood and Earnshaw (p. 1116) write "Rhodium and iridium...are especially notable for their extreme inertness to acids, even aqua regia. Dissolution of rhodium metal is best effected by fusion with NaHSO4, a process used in its commercial separation." Double sharp (talk) 11:00, 7 August 2016 (UTC)
+1 I know it from my own experiments too. I clean always Rh (and Ir) shavings with aqua regia with no Rh losses (or "only" µg amounts). --Alchemist-hp (talk) 13:24, 7 August 2016 (UTC) P.S: take a look above to the POTD ;-)
Furthermore, Greenwood and Earnshaw also give the actual account of the history. "In 1803 both rhodium and iridium were discovered, like their preceding neighbours in the periodic table, ruthenium and osmium, in the black residue left after crude platinum had been dissolved in aqua regia. W. H. Wollaston discovered rhodium, naming it after the Greek word ῥὀδον for "rose" because of the rose-colour commonly found in aqueous solutions of its salts." I'll make the necessary changes. Double sharp (talk) 14:16, 7 August 2016 (UTC)
Thanks for the changes. Rh and Ir are better soluble in a mixture of NaClO3 + conc. HCl. Ru + Os in a solution of LiClO. --Alchemist-hp (talk) 17:25, 7 August 2016 (UTC)