Talk:Promethium

message: OK, what is a semi-stable isotope? —The preceding unsigned comment was added by 12.41.204.3 (talk) 22:32, 5 December 2006 (UTC)
replies: text: I would think it's an isotope of a particular element that is still radioactive, but is relatively stable (has a long half-life) compared to other radioactive isotopes. You might find more answers on other pages. AstroHurricane001 22:53, 5 December 2006 (UTC)
replies: text: A semistable isotope is one like bismuth-209, element-83, which has 
a half-life estimated at about 10^23 years. A tiny bit of alpha decay has been observed in "miraculous" experiments done in exotic semiconductors at temperatures close to absolute zero. 10^23 years is far longer than the life of the known universe, and it used to be thought that bismuth-209 was stable. 47.215.188.197 (talk) 08:38, 8 February 2017 (UTC)
thread_title:  semi-stable isotope  

message: This article states the appearance but does not have a picture of the element. This is peculiar.  — Preceding unsigned comment added by 220.245.49.25 (talk) 05:15, 24 April 2014 (UTC)
replies: text: Yes, we're aware of this problem, and we've been looking for a reliable one for years. (Hence the banner at the top of this talk page with the camera in it, requesting a photograph.) Unfortunately, nobody seems to have actually photographed something that is incontrovertibly a pure promethium sample, and therefore there is no image of pure Pm metal on this article. (We do have one for promethium(III) oxide, though.) Double sharp (talk) 12:44, 24 April 2014 (UTC)

text: No.  is Nd by T.W. Gray , and  is a colored/decolorized illustration from . Materialscientist (talk) 23:24, 22 January 2015 (UTC)

text: The first one is a Nd-Fe-B magnet according to the caption. The second is the picture of Nd used in Ralph Lapp's book Matter with a recoloured background. Double sharp (talk) 19:33, 12 June 2015 (UTC)

text: Yes, but for such a rare element, I'd expect a long explanation of how the sample was made, which I don't see there. (And I'd expect larger safety precautions, as Pm stored out in the open in such large quantities is going to cause heavy radioactive contamination.) And given that most pictures of Pm online happen to be actually Nd, I'm really not convinced by this picture, and probably won't be until it can be proven to be unquestionably Pm. Double sharp (talk) 10:40, 15 June 2015 (UTC)
thread_title:  Image 

message: When did its name change from prometheum to promethium, and why? I'm sure I remember as a kid (late 1970s) the -eum spelling ... - David Gerard (talk) 20:24, 3 January 2016 (UTC)
replies: text: My question is was it ever publicly referred to as "prometheum"? My reading of this article is that the name was derived from Prometheus but that the second "e" was changed to "i" when the element name was proposed and that this "-ium" spelling is all that was ever published. However, without reading the actual source I can't be sure. If my reading is correct, there is no need for the "formerly prometheum" note as that spelling would never have really existed.--Khajidha (talk) 12:44, 15 September 2017 (UTC)
thread_title:  Name change - when and why? 

message: the first paragraph of Applications says that Pm147 can not emit gamma radiation, and the first paragraph of Precautions says that it can. i'm not sure which is correct, hopefully someone else can revise.  WordsAndNumbers (talk) 05:30, 15 October 2021 (UTC)
thread_title:  article contradicts itself re: Pm147 emitting gamma radiation