Talk:Iodine/Archive 1

Vandals
Please stop your purile behavior on this page PrometheusX303 00:55, 21 March 2006 (UTC)

137Cs
I doubt that a person could safely take enough KI to flush 137Cs after a nuclear fission "event" (fallout). I would tend to recommend KCl, which is even used as a table salt substitute (mixed with NaCl). I am working this with an expert chemistry professor and when I hear back I may change the page on the aesium item. Carrionluggage 07:06, 27 January 2006 (UTC)

Indeed, you couldn't do it safely with KI. You might run Cs out a little faster by taking a potassium supplement, but it would have to be at medical doses (4 grams a day of K or so as slow release tablets). The biological half-life of Cs is short, and its radiologic life is irrelevent. I don't think there's much point in worrying about Cs-137 as it doesn't build up in the body (running out like potassium) no matter what you do. For a dirty bomb using fission products, the next worst isotope to worry about, after I-131, is Sr-90, which collects in bones and causes a severe dose that way. Take your TUMS to help prevent that ;).  Sbharris 05:37, 19 May 2006 (UTC)

Acid confusion
The history section mentions treating seaweed ash with hydrochloric acid and then in the next sentence replaces it with sulfuric acid. Apparently one is wrong, but I don't know which one is correct. Anyone able to fix this up? --66.188.84.209 07:56, 20 Jan 2005 (UTC)


 * The iodide in the seaweed ash needs to be oxidized in the presence of acid, so sulfuric or nitric acids would work, but not hydrochloric. Hydrochloric acid can be used with a suitable oxidizing agent such as hydrogen peroxide.--24.16.148.75 17:25, 25 June 2006 (UTC)

Isotopes
Mistakes about Iodine 131:

The I-131 is a beta and gamma emissor, and its energy are 192 keV (beta) and 364 Kev (gamma). The info is wrong, as you can see at http://www.iem-inc.com/toolabsr.html or http://www.rxlist.com/cgi/generic4/nai131.htm

--Saragc 08:46, 26 July 2006 (UTC)

ion Isotopes says: "129I (half-life 15.7 million years) is a product of 129Xe spallation in the atmosphere" and later in the same section says: "129Xe in meteorites have been shown to result from decay of 129I"

I am confused. In the end, 129I generate 129Xe or 129Xe generate 129I ?193.52.24.125 13:08, 1 May 2006 (UTC)


 * I don't know the answer for sure on the spallation, but can tell you that the I-129 to Xe-129 transformation by beta decay is correct and has been used for dating (don't ask me how, since the 15 MY life is too short, I would think, for solar system objects-- all primordial I-129 is gone so all the Xe-129 you find in I is from I-129, but so what?)
 * As for I-129 produced in the atmosphere from Xe spallation, I've read that, but nobody says what isotope of Xe it's from. My guess is that your statement that it's Xe-129 is in error (somebody's assumption). I'd demand a source for it, or delete or change to generic Xe. Spallation knocks particles off. If a proton comes in (and essentially it's always a proton for cosmic rays) and a proton goes out, you get no net change. If you have proton in neutron out (p,n) then you get an isotope which increases by atomic number, and here we want to go the other way from Xe(54) to I(53) which means we need to lose a net proton. The only good way to do that is with a proton in, is a 2 proton out scheme (p,2p) and in that case your atomic number goes down by one, so if you want I-129 you need to start with Xe-130 and basically knock 1 net proton off it. Fortunately, 4% of naturally occuring Xe in the atmosphere is Xe-130. My guess is that's where the I-129 is from.Sbharris 20:32, 25 May 2006 (UTC)

Tincture of Iodine
I believe sodium iodide is a component as well, in fact with this the alcohol is not necessary.


 * Technically, alcohol is needed for "tincture" (see tincture of iodine, but there is a Lugol's iodine as well, which is the K+I3- solution you describe. Isn't WP amazing? I'll add the links.Sbharris 23:23, 7 June 2006 (UTC)


 * Yes, but the alcohol is added just to make it 'sting'. Without that, youngsters might actually be more co-operative...

Tincture of iodine is a solution of 2-3% iodine in ethanol. Lugol's iodine is a solution of iodine in potassium iodide. Kyanite 01:01, 18 September 2006 (UTC)

Question about volumetric iodine solution
Could anyone explain to me why a 0.1M iodine solution sold for volumetric analysis is sometimes quoted as 0.1M (0.1N) and sometimes as 0.1M (0.05N)? What is actually in this solution? Thanks! OAP boba 08:20, 27 April 2006 (UTC)


 * Here's an MSDS for 0.1 N volumetric iodine solution, and it's not much help. . Yeah, they put 12.7 g iodine in a liter, which means it's 0.1 N if (and only if) your "formula" to make up the solution is is I and nothing but I. (Normality is formula weight per liter solution). But everybody knows that the stuff added as "I" is the solid I2, and when you add it to KI in water (as here, because this solution also contains more K+ and I- than I) it turns into I3-. So "normal" is meaningless in this situation, and so is "molar". You have 0.1 mole titratable elemental iodine per liter. But that's not 0.1 molar, since most of this stuff is in the form of I3-. These solutions are 4% KI, which means they are 0.24 molar in K+ and 0.24 molar in I-, or would be if the I2 wasn't added. As it is, the I2 is added and 0.1 mole/L reacts with I-, so the solution is probably 0.24 molar K+, 0.1 molar I3-, and (the remaining unreacted) 0.14 molar I- or so. Since there is no valid formula weight being used, all motions of "normal" are out the window, IMHO.  S  B Harris 02:53, 27 October 2006 (UTC)

Sublime vs. sublimate
Sublimate is the proper verbal form of the noun sublimation (see sublimate vs sublime à la American Heritage). It makes more sense, and follows more logically, from sublimation. It also has no other definitions, whereas sublime is more commonly associated with things unrelated to Chemistry.&mdash;Kbolino 05:14, 21 March 2006 (UTC)


 * Sublimation is the derivative, not the basic term; talking about sublimate following "more naturally" from sublimation is therefore erroneous. Anyway, in the Merriam-Webster dictionary, sublime is the basic form ; sublimate merely has a redirection to sublime . Sublimate seems to be a back-formation from sublimation in much the same way as orientate was formed from orientation. Thefamouseccles 06:41, 29 July 2007 (UTC)

Neutron amount?
the first time i looked up iodine on wikipedia was 09/02/2008. for my research i had to write down the mass number and atomic number of iodine. my first intention was the read the info off the periodic picture on the right, but the number of neutrons was 76 (Image:I-TableImage.png) where the number of neutrons in the article was 74. although this is a small problem it is a problem none the less, and i would like to see the some correction. —Preceding unsigned comment added by 218.215.95.238 (talk) 23:15, 8 February 2008 (UTC)


 * The "76N" in the table is wrong. The figure of 74 neutrons is correct for the only stable isotope, I-127. So the figure needs to be changed. I've left notes on some pages to see if the makers will do it. Thanks for pointing this out. S  B Harris 01:43, 12 February 2008 (UTC)

"Price" section
Why is this section even here? The value of things always change; the reader does not need numbers to understand that concept, or a whole section comparing the price of iodine year after year to get the point. A simple sentence about the increased value of iodine should suffice. Section also illustrates one point of view by stating the US dollar price. Other weaknesses such as sentence structure, grammar, and 1st person narrative tone pointed out that the section needed deletion until much further improvment and editing!--Stoa 05:04, 5 November 2007 (UTC)
 * We've all tried to get prices out of these element articles for this very reason. Unless the price is amazingly high or low, it's just not very useful since it's currency, time, supplier, and (most importantly) purity-dependent. I'll take it out. S  B Harris 01:44, 12 February 2008 (UTC)

Sublimation
It is a well known fact that iodine sublimes, but is it actually true? Sublimation is the transformation of a solid to gas without melting. Since Iodine has a melting point well below its boiling point it seems very strange that it would undergo sublimation. Apparently people seem to think that iodine sublimes because when they look at the solid they can see vapor rising up from it, which is only normal, since every solid, or liquid for that matter, is always in equilibrium with its own vapor. Since iodine has a visible vapor people mistake it for the process of sublimation.


 * Yes, it's true. All solids sublime to some extent, but some so slowly that it can be ignored. Since iodine vapour is so colourful, it gets noticed. JohnSankey 14:43, 27 September 2005 (UTC)


 * Sublimation has nothing to do with melting and boiling points. Water melts at 0 and boils at 100, but ice in a freezer evaporates without melting. Barnaby the Scrivener (talk) 12:19, 25 July 2008 (UTC)

Donald W. Miller
Why is this person singled out to have his opinion in the Human Dietary Intake section? Maybe it could be mentioned that some experts dispute the RDA, but it currently doesn't sound very encyclopedic. —Preceding unsigned comment added by Mpk138 (talk • contribs) 21:23, 11 September 2008 (UTC)

Cleanup
I've tried to clean up with the production/occurrence and the compounds.

The radioactive iodine topic is sprinkled all over this page, which makes it messy and repetitive. I was thinking of shifting all that to iodine-131, summary style, when I realized that radioactive iodine is not only the 131 isotope. Ideas? --Rifleman 82 (talk) 08:30, 12 December 2008 (UTC)

Iodine and acne
Bold textI am not a student, teacher or professor or any type of learned person. I am just a mother. I have bought my son the kit called PROACTIVE it is for skin care. While reading it I noticed it repeated stating not to consume more then the RDA of iodine.... as we all know this is in many things we consume daily without us knowing. I also give him vitamin supplements including FOLIC ACID. Am I doing his acne more harm then good. I checked even milk has iodine in it. 24.213.77.139 (talk) 01:39, 23 March 2009 (UTC)Brenda


 * I deleted the email adress. --Stone (talk) 05:47, 23 March 2009 (UTC)


 * High school dietary dairy intake and teenage acne
 * Dairy and acne—the iodine connection
 * Acne and milk, the diet myth, and beyond

A letter, Dairy and acne—the iodine connection, from Harvey Arbesman, MD, (Departments of Dermatology, and Social and Preventive Medicine University at Buffalo School of Medicine and Biomedical Sciences) suggests a link between iodine and acne, but clearly states that this is not yet (2005) proven by any science study.--Stone (talk) 07:56, 23 March 2009 (UTC)

Tungsten essential to some organisms, and heavier than Iodine.
The article states "Iodine is an essential trace element, the heaviest element known to be needed by living organisms."

But the article on Tungsten states "Tungsten is an essential nutrient for some organisms."

Tungsten's atomic weight is 183.84 and its atomic number is 74 and its density is 19.25  g·cm-3. Iodine's atomic weight is 126.90447 and its atomic number is 53 and its density is 4.933  g·cm-3.

Tungsten is heavier than Iodine unless the meaning of "heavier" is one I haven't thought of.

Isn't tungsten an "element known to be needed by living organisms"?

Eldin raigmore (talk) 20:27, 16 May 2009 (UTC)
 * Good catch! Both articles needed to be changed. Iodine is far more common in life, but tungsten is indeed used by a few bacteria, and is far heavier. S  B Harris 02:41, 17 May 2009 (UTC)

how to take iodine out of iodized salt
what would i need to take the 45% iodine out of 1lb of iodized salt —Preceding unsigned comment added by 63.3.5.4 (talk) 01:19, 27 July 2008 (UTC)
 * The 45% in the nutrition facts label doesn't refer to composition (that's a lot of iodine!) but refers to daily percent value, which for iodine should be very low. In any event, there is not nearly enough iodide in iodized salt to extract any meaningful amount of it in one pound of salt anyway. —Preceding unsigned comment added by 98.229.181.57 (talk) 04:13, 21 December 2009 (UTC)

Staining
Iodine can be used as a stain when viewing cells under a microscope. Someone should add this to the "Uses" section.

Can Iodine alone be used to stain cells? I know it's used in some staining procedures--for examples, Gram stains--but how does it stain cells by itself and when would this be used? --Dead mellotron (talk) 03:46, 10 February 2010 (UTC)

Undue weight on specialized medical issues?
By my reading, the article gives Undue weight to relatively specialized medical issues related to cancer, immunity, and salivary iodine. If one has been affected, then these problems certainly do not seem specialized, but in the broad overview of an element, the length and 20 fairly primary citations imply disproportionate significance. A shorter section supported by a few general references would probably better serve the readership. Other suggestions: (1) "Biological role" and "Extrathyroidal iodine" should be blended to minimize redundancy and make the message clearer and (2) "Human dietary intake" and "Deficiency" could also be blended since the point of dietary intake is to avoid deficiency. --Smokefoot (talk) 16:48, 16 July 2010 (UTC)
 * Agreed. The section(s) on iodine in biology should certainly be no longer than the section for "sodium in biology" in the Sodium article. There is a main Iodine in biology wiki, but the problem is that it got to be a repository for Venturi's views of the role of iodine in evolution, and then got cut back, and so there's now more info in the iodine article than there is in this subarticle. I'll see if I can summarize some info in the main element article and move it to the iodine in biology article, per WP:SS. Also, the info on radioiodine can be summarized in the isotope section here, and the rest go into the Isotopes of iodine article. S B Harris 20:47, 16 July 2010 (UTC)
 * LATER Okay, that's done. Article has been cut from nearly 60 kB to 53 kB. All of the missing info is in {main} subarticles isotopes of iodine and iodine in biology, with summary left behind. I've also rearranged some stuff so all the bio-med isotope applications are in that section, and all the nutrition and biology stuff now goes more smoothly, as suggested by Smokefoot immediately above. See what you think. S  B Harris 06:17, 17 July 2010 (UTC)


 * Looks better to me, but I tried to consolidate some of the sections further. Incidentally, the chemistry section needs to be updated to put these various reactions into their context in the world and impact...  II  | (t - c) 07:34, 17 July 2010 (UTC)

The Japanese and autoimmune hypothyroidism
I've removed the Patrick 2008 reference to the Journal of Alternative Medicine since it's just not factual. Of course the Japanese have a high incidence of autoimmune thyroid disease-- see Hashimoto's thyroiditis. And they have more near the coastal areas. The role of iodine is heavily under debate in this: and Wikipedia is not the place to debate it. A general article is not the place to float pet theories on the role of iodine in gastric cancer, etc. Epidemology is not secure for making these generalizations. And even if we had very good evidence, it would merit only one line in a general article on iodine. We need a subarticle on Iodine in biology (which I just created as a stub) to put a lot of this stuff into. S B Harris 05:27, 26 July 2009 (UTC)

"Precautions and toxicity of elemental iodine

Elemental iodine is an oxidizing irritant and direct contact with skin can cause lesions, so iodine crystals should be handled with care. Solutions with high elemental iodine concentration such as tincture of iodine are capable of causing tissue damage if use for cleaning and antisepsis is prolonged.

Elemental iodine (I2) is poisonous if taken orally in larger amounts; 2–3 grams of it is a lethal dose for an adult human."

First, I'm new to this and don't know the right way to do things here, so please excuse me. I'm concerned because the above advice is both unsourced and dangerous. Wikipedia should not use unsourced information about lethality ever. "Common knowledge" can be a commonly believed untruth. According to Redox, who are as good an authority as you can get, http://www.redox.com/msds/data/iodine.html "Swallowed:    Corrosive! Can cause severe burns of the mouth, throat and stomach. Causes abdominal pain, vomiting, stupor and shock. Probable lethal dose is 2-4mg of free iodine." —Preceding unsigned comment added by 211.28.38.142 (talk) 15:13, 20 January 2010 (UTC)


 * 2-4 mg of free iodine as a lethal dose would make iodine about 20 times more toxic than cyanide. Given all the tinture of iodine out there with 20 mg free iodine per mL, I just don't believe it. Where are all the dead people, if a tenth of a mL (2 drops) of tincture of iodine is enough to kill you? This source recommends 5 drops (about a quarter mL) of 2% tincture of iodine per liter of water as a disinfectant. 5 drops is about 5 mg. Do they really want you drinking a lethal dose of iodine in every liter of water??  S  B Harris 21:18, 17 July 2010 (UTC)

Shouldn't Iodine be in Category:Biology and pharmacology of chemical elements ?
Shouldn't Iodine be in Category:Biology and pharmacology of chemical elements ? Eldin raigmore (talk) 20:48, 16 May 2009 (UTC)

I'm a little unsure about the statement that "iodine is essential to all living things." While it's vital in vertebrate development, and some archaebacteria have found mechanisms for coping with it, I was under the impression that iodide is actually quite toxic, which is why it's such a good germicide. Am I missing something?doctorwolfie (talk) 11:36, 28 August 2010 (UTC)

Deficiency
I looked into this statement, which seems a bit far fetched: "In Germany, it has been estimated to cause a billion dollars in health care costs per year."

The source for this statement is here: http://www.thorne.com/altmedrev/.fulltext/13/2/116.pdf

This paper has a further source listed as: Gutekunst R. Iodine deficiency costs Germany over one billion dollars per year. IDD Newsletter 1993;9:29-31.

Here is a link to the IDD Newsletter: http://iccidd.server295.com/media/IDD%20Newsletter/1991-2006/idd293.htm

'''I could not find any references to back up this statement. I propose the statement be removed from the page.""

Bentford (talk) 21:05, 26 February 2011 (UTC)


 * Yes, thanks. The Gutekunst article referenced is indeed not in that issue of the IDD newsletter. Perhaps it's in some other issue. Such a thing may be estimated by some German "natural hygeine" alternative medicine types, who want to treat everybody with iodine pills, to be responsible for every case of hypothyroidism found. But as you surmise, it's not the feeling of the average doctor or nutritionist, or the government of Germany. I'll remove it. S  B Harris 21:17, 26 February 2011 (UTC)

tungsten?
the text "Aside from tungsten, iodine is the heaviest element to be essential in living organisms, and iodine is the heaviest element thought to be needed by higher animals" appears to be saying that tungsten is essential to living organisms. I thought tungsten was somewhat toxic? -- Waveguy (talk) 18:52, 28 February 2011 (UTC)
 * Tungsten isn't needed by ALL living organisms, just a few bacteria. If it's needed by ANY living organisms, it's needed by "living organisms." (We should make this clear). Iodine is probably needed by all animals at least. I don't know if it's needed by all bacteria, or even plants. S  B Harris 19:38, 28 February 2011 (UTC)

quality scale assessment
B-Class review
 * The article is suitably referenced, with inline citations where necessary.
 * Several sections are unreferenced.
 * Characteristics — no reference for the whole section
 * Structure and bonding — no reference for the whole section
 * Production — the lab examples need a reference


 * The article reasonably covers the topic, and does not contain obvious omissions or inaccuracies.
 * OK


 * The article has a defined structure.
 * the production numbers are also in the occurrence section


 * The article is reasonably well-written.
 * Structure and bonding — what is a Cmca No 64 ?
 * Isotopes and their applications — Is this vandalism ? It can be administered to humans safely only in very high doses, which destroy all tissues that accumulate it.
 * Isotopes and their applications — MIBG does not need to be the acronym
 * Animal feed — the use of ethylenediammonium diiodide should be explained


 * The article contains supporting materials where appropriate.
 * OK


 * The article presents its content in an appropriately understandable way.
 * OK

needs work to stay B-Class

--Stone (talk) 20:15, 14 March 2011 (UTC)

Why change heading: "Protection from radioactive fallout
> Human health"?== The change of this heading is not a good one, imo. I came to this article to check for something like Protection from Radioactive Fallout because of this topic's current importance, but could not find anything, until I dug deeper into the history of this article. I hope someone changes the heading back to the original Ottawahitech (talk) 13:55, 15 March 2011 (UTC)
 * Because in terms of the APPLICATIONS of iodine, the amount of iodine used to make iodized salt (iodized salt contains "one part sodium or potassium iodide to 100 000 parts of sodium chloride." according to Ullmann's Encyclopedia) probably outweighs the consumption of iodide for people worried about radiation. People are jittery now and many vendors are selling worried people KI, I realize. But the use of KI by that tiny fraction of people living near Fukushima or Chernobyl does not compare to the billions of people that eat iodized salt every day, even at 1 part in 100,000.  But ideas on how to entitle this section are always welcome, because I was unsure.--Smokefoot (talk) 14:12, 15 March 2011 (UTC)
 * Thanks for the speedy response :-) Yes, I agree this is sensitive especially in light of the 5-fold increase in the daily visits to this article (see http://stats.grok.se/en/latest/Iodine ). How do others here stand on this question?~ Ottawahitech (talk) 14:28, 15 March 2011 (UTC)
 * Having writen a lot of this section as well as a lot of the potassium iodide where most of the radiation protection info is, I agree that the header really has to mention uses of KI in order of importance, and radioprotection is way down the list. Also, KI for radioprotection from I-131 is already mentioned in the isotope section. However, due to the unusual public interest here, I've been WP:BOLD and added several links to the potassium iodide article, and added "radiological use" last in the header, along with nutritional and medical uses. That should do it. If people are looking, they should have no troubling finding it now. S  B Harris 22:30, 15 March 2011 (UTC)

Picture
Where could this picture fit in? Lanthanum-138 (talk) 03:21, 5 June 2011 (UTC)

Bonding forces
Right now the page is very vague about the intermolecular forces between the iodine molecules. It is only stating "van der waals forces" which is split into three different categories. I am changing this to be more specific saying it is the van der waal London Forces attracting the molecules together. If anyone disbutes this, please edit it and not take out the information completely for this is an important specification to include. — Preceding unsigned comment added by Thephysicsnerd (talk • contribs) 14:24, 4 October 2011 (UTC)

Radioopacity
Some editor has a persistant delusion that iodine's radio-opacity (absorption of X-rays for medical imaging) is due to its valence electrons, and thinks that I am somehow misunderstanding this. But there is no meaning of the term "valence electron" in chemistry, physics, or medicine, which has anything to do with this. Iodine like all elements has a Thomson cross section (Thomson scattering) to X-rays that is determined by its mean atomic electron density (which is all electrons in the atom, not just the valence electrons), and also the mean electron density of iodinated contrast materials is further enhanced by their shear physical density (mass density-- as water liquid is more radio-opaque than steam). Finally iodine's photoelectric effect scattering potential begins to have an effect for X-rays more energetic than its K-edge absorption at 33 keV, and many X-ray machines are filtered to remove some X-rays that are lower in energy than this, especially when working with iodine contrast agents. That is all. The valence-pushing editor fails to understand this, and has not looked at the references I have provided. . He has an idée fixe about this, and I'm forced to keep reverting him. I am going to treat further interventions from him as vandalism. S B Harris 22:09, 26 May 2012 (UTC)
 * Yes, I saw that you were fending off edits by what is probably a child enamored with jargon. Hopefully they tire.  BTW, I agree that the bio-part of selenium is bloated, still. --Smokefoot (talk) 23:28, 26 May 2012 (UTC)

Source for Tincture of Potassium Iodide?
Hello. I am wondering if anyone has information on specifically where different brands of tincture of Iodine are sourced from? The article mentions iodine as coming from Chile and Japan and the US but not how to tell exactly where a particular brand's is from. What I am getting at is, due to the crisis in Japan, and the resulting radiological pollution of the Pacific Ocean that has resulted, obtaining iodine from kelps grown in the Pacific, especially near Japan might not be a good idea. Are there brands of tincture that come from other places? Thank you. 4.246.161.167 (talk) 22:19, 8 July 2012 (UTC)


 * A map: 4.246.161.167 (talk) 22:35, 8 July 2012 (UTC)


 * The article gives as source in Japan The Japanese Minami Kanto gas field east of Tokyo . This is salty brine from the underground. Old, may be millions of years old water. So Iodine is not produced from kelps in large scale anymore. --Stone (talk) 13:27, 9 July 2012 (UTC)
 * And even if it was, there's no reason for concern from I-131 from a reactor leak 16 months ago. This isotope has a half life of 9 days, meaning it's now decayed for 54 half-lives, giving it an activity less than 10-16 of what it was at its peak. Which is nothing. S  B Harris 18:03, 9 July 2012 (UTC)

Thanks for the info. The reactors are still reacting and unstable. #4 is completely open to the elements and could collapse. It's too hot to get near. The spent fuel pool is 100 feet off the ground. Fresh cesium and iodine are emitting daily. A lot of the radioactive water (which was being poured on it from above in an attempt to keep it cool) has gone underground as well. Here's a site that has been keeping track I think almost from day one. http://enenews.com/. So are you saying that Japan is the sole source for tincture of iodine? 4.246.165.212 (talk) 04:32, 10 July 2012 (UTC)
 * Fresh iodine-131 is not being emitted daily, because it's all gone. It is made only by fission and the fission stopped 16 months ago. After that, it decayed inside the reactor and is at levels of 10-16 of what it was there, also. I-129 has a half life too long to be dangerous. Fresh Cs-137 is a problem, but we're not talking about Cs here. S  B Harris 18:53, 10 July 2012 (UTC)
 * Clarification: See articles here on recriticality atFukushima. Note also that Iodine 131 was found in Japan many months after the original meltdowns. 4.246.166.224 (talk) 02:55, 11 July 2012 (UTC)
 * "Many months" means exactly what? 2 months? 3? We're now out at 16 months. Cite the latest month you have a report for. By April, 2012, I-131 levels had dropped below background limit of detection, though some Cs isotopes were still detectable. Are you being willfully scarmongering about I-131, or are you just unable to understand numbers?  S  B Harris 20:48, 11 July 2012 (UTC)


 * What is the argument? Did you even check the link I provided? If fission stopped March 11 or shortly thereafter and iodine 131 has a half life of 7 days how long until it would become pretty much undetectable? Not long. Yet iodine 131 was found in Tokyo in September, October, November, December of 2011 and January 2012, 6, 7, 8, 9 and 10 months after the meltdowns, the latter in snow "suggesting recriticality" (not my words). Even Tepco is acknowledging the possibility of recriticality in Unit #2 as recently as May 30 2012 . Anyway, I didn't come to argue but again to find out if there is a source for tincture that is not from Japan. 4.246.222.98 (talk) 01:28, 12 July 2012 (UTC)
 * As it is not produced from kelps and the water in the gas wells is million years old and has no connection to the to level ground water the iodine from Japan is as clean as the one from the US and Chile. Japan is the second largest producer after Chile, this can be seen on the map in the article.--Stone (talk) 08:26, 10 July 2012 (UTC)


 * Stone, see this article. . Thousands of tons of water have been poured on these reactors and leached into the ground. Fukushima is not that far from Tokyo. Note, I'm not trying to be alarmist here, just defend the point that an alternate source for iodine tincture would be good. 4.246.166.224 (talk) 03:20, 11 July 2012 (UTC)
 * Scientists reported radioactive 129I ages of 50Ma for the brines. This means they had no contact to the surface for million years. They are save. If there is a point of contact the gas in the deposit would come to the surface in no time. If you buy from a company from Chile everything is OK to.--Stone (talk) 08:23, 11 July 2012 (UTC)


 * Thanks Stone. I meant underground contact. More . I noticed that Tepco is building a wall to go 100 feet under and around Fuku to stop contamination . Course what's already out is out. Anyway, that takes me to my original question, how to tell where a particular brand is sourced from? Chile would be good I think. 4.246.166.30 (talk) 14:56, 11 July 2012 (UTC)

I should add that Iodine 129 has a half life a bit longer than 131. 15.7 million years. Both are released together. A picture of reactor #4. If it does collapse it would be prdent to have supply of (uncontaminated) tincture of iodine on hand I would think. 4.246.165.212 (talk) 05:43, 10 July 2012 (UTC)
 * With 15.7 million years half life  you only get a few decays in your personal life of 80 years, so it is not problematic. The iodine produced by Chernobyl and the US and USSR atomic tests every where in your food is the more problematic point.--Stone (talk) 08:26, 10 July 2012 (UTC)

Insoluble
I took out the mention of iodine being 'insoluble' - it's soluble in lots of liquids, as already noted in the next section. JohnSankey 14:43, 27 September 2005 (UTC)

Pranks?
Oh come on. I would like to see one single source for Nitrogen Triiodide being commonly used in college pranks. I will remove that sentence in a week or so if no one can provide one. I have known of its being used in a Harvard dormitory in 1953. Carrionluggage 07:06, 27 January 2006 (UTC) It was done when I went to college, in fact the Chemistry professors acknowleged it also happened when they went to college. It usually does not make the papers.

My A.P. chemistry teacher mentioned in passing that Nitrogen Triiodide had been used for pranks during his time as a student at the University of Washington. His comments encompassed the placement of the compound in question on door knobs and toliets. Kyanite 23:14, 11 September 2006 (UTC)

I was nearly kicked out of college for a prank involving nitrogen triiodide. 209.6.76.46 (talk) 15:55, 21 January 2013 (UTC)

Properties (Question about color)
...under standard conditions is a dark-purple/dark-brown solid.. In the image it more looked grey. -Yyy (talk) 10:27, 26 May 2008 (UTC)

As a grad student, I commonly use I2 in my research. It is definitely a metallic (not actually a metal, obviously) gray. I just went and looked at some to make sure. Hwinnian (talk) 20:34, 11 September 2008 (UTC)


 * All solid iodine i have seen, was grey, as in image (it stains most organic substances brown, though). Sublimated iodine was grey as well. Changing article. -Yyy (talk) 07:18, 1 March 2009 (UTC)

In AL chemistry course, I learnt that iodine vapour, when expose to white light, absorb yellow light of the visible light spectrum and gives violet itself. (Reason: Iodine molecules are comparatively large in Halogen family. It requires a smaller energy to promote 1 of its outermost electrons to the next higher energy level. By E=hc, we found that less amount of energy that is with smaller wavelength in the visible light spectrum is required for such a promotion.)

However, in AL physics course, I was told by a teacher that iodine actually absorb violet and then re-emit violet rather than absorb yellow and left violet to pass through it.

Could someone tell me which one is correct?


 * In either case substance will appear to be violet. I do not know for sure, but iodine vapor seems to be quite opaque (there is not much light passing through). If this is so, then there would be only absorbed and reflected light. Substance, which looks violet, reflects violet light and absorbs most of other wavelengths. It most probably does not absorbs and reemits violet, because in cases of fluorescence (i cannot imagine any other explanation), emitted wavelength is longer than absorbed. -Yyy (talk) 07:18, 1 March 2009 (UTC)

I have never seen pure elemental iodine look gray. It is always a dark silvery-purple/violet color. The vapor is an intense purple color. — Preceding unsigned comment added by 209.6.76.46 (talk) 16:01, 21 January 2013 (UTC)

Solubility
The first sentence in this section states "....iodine is highly soluble in nonpolar organic solvents, including ethanol.....acetic acid.....glycerol..." with other nonpolar solvents mentioned in between. To the best of my (limited) knowledge, ethanol, acetic acid and glycerol are polar solvents. Is it just the way the sentence is worded that has me confused? Thanks. Kclongstocking (talk) 02:20, 27 February 2013 (UTC)

Edit today
I reverted the pending change stating that saltpeter produced from pig manure required sodium carbonate. If memory serves, pig manure is a natural source of KNO3 and therefore wouldn't need Na2CO3 in preparation. Additionally it makes the preceding material look like it is cited by a source when it isn't. I may be completely wrong, though, in which case my revert should be undone. Double sharp (talk) 14:40, 13 August 2014 (UTC)

Iodine in the air
Does Iodine in the air play a biological role for humans, or is neglegible? It is said that holidays at the seaside are healty for people with a iodine deficiency. --37.191.130.26 (talk) 14:48, 29 August 2014 (UTC)

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Electronegativity of nitrogen
I've added nitrogen to the list of elements (oxygen and the first three halogens only, in previous versions) that technically can't form iodides because they are more electronegative than iodine; "nitrogen iodides" are technically iodine nitrides. Nitrogen is more electronegative than iodine; this fact is in no way a matter of controversy or a close call. Don't be fooled by the unreactivity of N2 gas; awesome power lurks beneath the sedate stability of that triple bond.

—Syrenka V (talk) 22:01, 17 March 2018 (UTC)
 * I've also added a note that NI3 is usually called nitrogen triiodide anyway, because it is closely analogous to the other nitrogen halides. Double sharp (talk) 05:12, 10 April 2018 (UTC)

Suggestion
Concerning "It is even less abundant than the so-called rare earths": The rare earths article linked almost immediately informs that they " are...relatively plentiful in Earth's crust". I don't know if that's true, but if so the first statement is perhaps misleading.

I'm not a professional Suggestor and only mean to help- thanks Krisandtim (talk) 15:21, 4 November 2017 (UTC)
 * That is actually the point, and it is why the rare earths are prefixed here with "so-called". Even the least abundant of them, thulium, is actually more abundant than iodine, which says a good deal about how the supposedly "rare" elements are actually more common than the more famous ones like iodine. Double sharp (talk) 16:26, 4 November 2017 (UTC)

fair enough, thanks- krisandtim  — Preceding unsigned comment added by Krisandtim (talk • contribs) 18:38, 17 April 2018 (UTC)

Least Reactive
I had thought Astatine is the least reactive of the halogens. It does say Astatine is more electropositive, but I thought Astatine was expected to be less reactive even though not enough of it can be collected to do much experimentation with.

Show the experimental data...
 * Astatine is rather ambiguous between halogenic and metallic properties. But all right, changed to "least reactive of the stable halogens". Double sharp (talk) 07:33, 5 April 2020 (UTC)

Iodine value
I wanted to clean up the section on iodine value which is currently incomprehensible, but I couldn't figure out what it was trying to say about iodolipids or how that was relevant to iodine value. There should probably also be a reference specifically for the statements about iodine value. I would appreciate if a more experienced editor could take a look.

PlutoniumJesus (talk) 08:33, 6 June 2020 (UTC)

Cristal structure
From the picture, it does not look face-centered, but rather base-centered. The I2 molecules at the center of the faces do not have the same orientation as the base ones.Ederag (talk) 12:55, 4 January 2022 (UTC)


 * User:Ederag is correct. The image is based on COD entry 9008595, itself from Wyckoff. The space group is given as Bmab, which is effectively the same as Cmca, number 64. As noted at Orthorhombic crystal system, this is base-centred. --Ben (talk) 20:40, 2 October 2022 (UTC)
 * Done. DePiep (talk) 21:30, 2 October 2022 (UTC)

Solubility
I suggest to add more info on solubility in various organic solvents at room temperature. AXO NOV (talk) ⚑ 11:56, 15 June 2023 (UTC)