Talk:Rubidium/Archive 1

Archive 1

Effects of its radioactivity

I removed this sentence from the text:

However, taken in excess it can be dangerous, as it is slightly radioactive.

It's wrong because its radioactivity is so weak, that it has no noticeable effect.

A gram of rubidium has 6 * 10²³ * 0.278 / 85 = 1.96 * 10²¹ radioactive atoms. Its half-time is about 1.54 * 10¹⁸ seconds, so each gram of naturally occuring rubidium has about 650 radioactive disintegrations/second. Each disintegration releases 0.283 MeV of energy, so that's 184 MeV released/gram/second.

Assuming an average person consumes some rubidium, one would absorbe 4 * 10^-10mS/gram of Rb/second (might be an orders of magnitude higher), that's 0.01 mS/year, which is well below the 2.4 mS/year background radiation, let alone the 200 mS limit under which there is no statistically significant danger. bogdan (talk) 23:32, 28 March 2009 (UTC)

Precautions

Rubidium reacts violently with water and can cause fires. To ensure both health and safety and purity, this element must be kept under a dry mineral oil, in a vacuum or in an inert atmosphere.

I have heard it will form unstable peroxides when kept under mineral oil. Maybe that will not happen if dry, I don't know. —Preceding

Jokem (talk) 13:10, 10 April 2009 (UTC)

History: extraction of rubidium salts from mineral water by Bunsen

According to http://en.wikipedia.org/wiki/Caesium#History and the German language article on Rubidium, Bunsen discovered rubidium's spectral lines in mineral water and also processed 44,200l of it in order to extract about 9g of rubidium chloride. I haven't heard of him extracting it from lepidolite (despite the German source noted) and there is no mention of it on the German wikipedia or the (English) caesium article. Does anyone have more information on this?

In any case, I believe the information from the caesium article should be incorporated into this one. —Preceding unsigned comment added by 95.223.228.160 (talk) 03:58, 26 January 2010 (UTC)

Refs 2 states in the introduction that the caesium was found in the mineral water on the thid page it starts with:

Behandelt man sächsische Lepidolith nach einer der bekannten Bethoden, durch die Alkalien von den übrigen Bestandtheilen getrennt für sich in Lösung gehalten werden, und fällt man eine solche Lösung durch Platinchloride, so entsteht ein Niederschlag, der, im Spectralapparat geprüft nur Kaliumlinien erkennen läßt. Wird dieser Niederschlag widerholt mit kochenden Wasser ausgezogen und zwischendurch im Spectralapparat geprüft so zeigen sich zwei neue prachtvolle violette ....... Wir schlagen daher für diese Alkalimetall, mit Beziehung auf jene besonders merkwürdigen dunkelrothen Spectrallinien die Benennung Rubidium mit dem Symbol Rb, .....

This makes it 100% clear that the first isolation was done from lepidolite. The article is written in a way that it does not give the time sequence of the discovery and in which sample the first rubidium or caesium was discovered by spectroscopy, but it is clear that Rubidium (1.1850 gramm of rubidium chloride) was produced from lepidolite and caesium from mineral water residues. The advantage of lepidolite was that it contains only traces of caesium. The extraction of the mineral water residues yielded the 9 and 7 gramms of rubidiumchloride and caesiumchloride. Which was more than from the lepidolithe, but it was hard to seperate the both. --Stone (talk) 07:21, 26 January 2010 (UTC)

Use in fireworks

I removed this sentence:

Rubidium compounds are sometimes used in fireworks to give them a purple color.

as rubidium is most definitively not used in any commercial fireworks (and it gives a red flame color, not purple). AFAIK it's not used in home-made fireworks either, but some idiot may have tried it. —Preceding unsigned comment added by 62.3.121.230 (talk) 00:20, 29 January 2010 (UTC)

Several idiots tried it and published it in an book and a peer reviewed journal. Pyrotechnic Chemistry and therefore I put it back into the article! --Stone (talk) 08:13, 29 January 2010 (UTC)

Origin of name

I doubt the statement about the origin of the name Rubidium being the colour of the flame. Most references speak of red spectral lines that the discoverers observed from flame spectroscopy. One web page that I found seems to include statements from them: http://web.me.com/dtrapp/Elements/color.html

On 23 February 1861 Bunsen and Kirchhoff reported that dissolving alkalies from lepidolite from Saxony, followed by precipitation by platinic chloride and repeated washing with boiling water, revealed two new spectral lines of a magnificent violet. Additional washing revealed red, yellow and green lines not belonging to other elements. Among them we may mention two remarkable red lines... located at the extreme red end of the spectrum... (which) led us to give this element the name Rubidium and the symbol Rb from Rubidus (Latin) which, with the ancients, served to designate the deepest red.

Can someone locate something definitely authoritative as a reference? 199.247.253.43 (talk) 08:42, 23 March 2010 (UTC)

From the cited source of Bunsen:

....Unter denselben sind zwei rothe dadurch merkwürdig, daß sie noch jenseits der Frauenhofer'schen Line A oder der mit dieser zusammenfallendedn Line Kaa, also im aller äußersten Roth des Sonnenspectrums liegen. Wir schlagen daher für diese Alkalimetall, mit Beziehung auf jene besonders merkwürdige dunkelrothe Spectrallinien die Benennung Rubidium vor mit dem Symbol Rb von Rubidius, welches von den Alten für das dunkelste Roth gebraucht wurde....

--Stone (talk) 11:00, 23 March 2010 (UTC)

Oh, thanks. That was a quick fix. 199.247.253.42 (talk) 04:26, 24 March 2010 (UTC)

GA Review

This review is transcluded from Talk:Rubidium/GA1. The edit link for this section can be used to add comments to the review.

Reviewer: Nergaal (talk) 04:34, 8 March 2011 (UTC) GA review – see WP:WIAGA for criteria

1. Is it reasonably well written?

   A. Prose quality:

   B. MoS compliance for lead, layout, words to watch, fiction, and lists:

2. Is it factually accurate and verifiable?

   A. References to sources:

   B. Citation of reliable sources where necessary:

   C. No original research:

3. Is it broad in its coverage?

   A. Major aspects:

   B. Focused:

4. Is it neutral?

   Fair representation without bias:

5. Is it stable?

   No edit wars, etc:

6. Does it contain images to illustrate the topic?

   A. Images are copyright tagged, and non-free images have fair use rationales:

   B. Images are provided where possible and appropriate, with suitable captions:

7. Overall:

   Pass or Fail: -->

Specific comments:

• "s the second most electropositive of the non-radioactive alkali elements and melts at a temperature of 39.3 °C (102.7 °F)" - poor sentence; also say that the most elpos is Cs; I think correct is alkali metals not elements
• repetition of "Like other" - use similarly to, etc
• "and does not normally occur in living organisms" - link it better to the previous sentence
• "property could be " - may prove useful
• first para in compounds is unreferenced
• radioactive87Rb - spacing
• "Natural rubidium is radioactive with specific activity of about 670 Bq/g, enough to expose a photographic film in approximately 30 to 60 days" - super interesting but needs citation and mention at what distance
• how about non-natural isotopes?
• any idea why is there so much Rb-87?
• Who is the main producer of the element? (country)

*"m limits its production to 2 to 4 tonnes per year." - in metallic form?

• the history section is thin outside of the discovery information

  There are several points in the other sections but than we have it two times mentioned

• asubchloride - spacing
• with carbon - was it actually coal?
• " The distilled rubidium was pyrophoric and the density differed less than 0.1 g/cm3 and the melting point by less than 1 °C from the now established values" - poor prose
• "0.24 % rubidium oxide" - which one?
• why both uses and appications?

Will do the last two sections a bit later. Nergaal (talk) 04:48, 8 March 2011 (UTC)

More:

• the intro says the metal is soft twice, but the body does not say anything about that
• the ionization energy (which is very low) should probably be included in the text
• I suggest moving the first para of application to history since it fits there better if you rename the latter just applications
• "(that is, producing volumes of magnetized 3He gas, with the nuclear spins aligned toward a particular direction in space, rather than randomly)" should be moved out of the paranthesis
• " LPRO series from Datum" - wikilink? anyways, without explaining the acronym it is pretty useless to the reader
• Rubidium-82 is first discussed in the aplications section, althoug stuff like lifetime and possibly the decay pathways shoudl be in teh isotopes section
• btw, what does Rb-87 decompose to? i.e. decay pathway

  I think it is already in the isotope section.--Stone (talk) 00:15, 14 March 2011 (UTC)

• wikilink strontium-82 and probably state its lifetime or rate of transformation into Rb-82
• "this element is kept" change that to metal
• "almost always has +1 oxidation state when dissolved in water" - two points: when it does not? and the oxidation state discussion should be above, not in the precautions section
• "The ions are not particularly toxic, a 70 kg" => "The Rb+ ions are not particularly toxic as a "
• "Rubidium was tested for the influence on manic depression" - should be in the uses section not the precautions one
• "died after a few weeks" - might be nice to be a little less vague

Most of the issues I've listed are easily fixable so I will leave this review open for a few days. Nergaal (talk) 08:02, 8 March 2011 (UTC)

A few more things:

• the term Rubidium standard should probably be mentioned
• Rubidium chloride has some nice aplications - maybe borrow some?

  Borrowed only one the others are very special lab applications

• RbOH is highly corrosive
• flame test for Rb should be mentioned
• any idea what is the typical coordination number for Rb?
• File:Rubidium-oxide-unit-cell-3D-balls-B.png might be nice to use to show tetrahedral coordination

  The coordination chemistry turned out to be complex so I would not like to go into detail here.--Stone (talk) 23:26, 19 March 2011 (UTC)

Nergaal (talk) 08:18, 8 March 2011 (UTC)

I don't have sufficient time for a few days, but will take a closer look at the article after Monday. Nergaal (talk) 17:31, 20 March 2011 (UTC)

No problem! I have also a lot of other things to do.--Stone (talk) 21:51, 20 March 2011 (UTC)

• Nice work! Although a few issues are left, most of them were fixed. Therefore, I am passing this article. Nergaal (talk) 21:44, 24 March 2011 (UTC)

Assessment comment

The comment(s) below were originally left at Talk:Rubidium/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

*the use section is a mixture of possible future applications and important uses without the possibility to find the difference.

Last edited at 22:25, 30 September 2008 (UTC). Substituted at 05:01, 30 April 2016 (UTC)