Talk:Sodium

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Version 0.5
Peer review This Natsci article has been selected for Version 0.5 and subsequent release versions of Wikipedia.
Wikipedia CD Selection
WikiProject icon Sodium is included in the Wikipedia CD Selection, see Sodium at Schools Wikipedia. Please maintain high quality standards; if you are an established editor your last version in the article history may be used so please don't leave the article with unresolved issues, and make an extra effort to include free images, because non-free images cannot be used on the DVDs.
 
WikiProject Elements (Rated C-class, Top-importance)
WikiProject icon This article is supported by WikiProject Elements, which gives a central approach to the chemical elements and their isotopes on Wikipedia. Please participate by editing this article, or visit the project page for more details.
C-Class article C  This article has been rated as C-Class on the quality scale.
 Top  This article has been rated as Top-importance on the importance scale.
 

nuclear reactor cooling[edit]

I strongly disagree with the wording of this paragraph. "Other uses" is not the place to talk about accidents or undocumented nuclear safety. I would just mention some examples of sodium cooled reactors like Monju (where the mentioned accident happened) in Japan or Phénix and Superphénix in France. --Zakatan (talk) 12:46, 14 July 2010 (UTC)

Occurences[edit]

I changed "different ['different what']" to "different minerals". I also changed "salt" to "halite". Eldin raigmore (talk) 20:48, 16 December 2011 (UTC)

That was because of 19:49, 16 December 2011‎ 66.219.235.208 (talk)‎ (36,866 bytes) (→Occurence: needs clarification, [Sodium] is found in many different, .... (different what?)). Eldin raigmore (talk) 21:00, 16 December 2011 (UTC)

Biological role of sodium[edit]

There is an error in the section on the biological role of sodium.

It states that the DRI for sodium is 1.5g per day. That is the DRI for those over 50, or with medical conditions such as hypertension. The DRI for the population that doesn't fall into these categories is 2.3g per day. See reference 49

It is also stated that the average American consumes 2.3g of sodium per day. The average amount is actually 3.4g per day. See reference 49 — Preceding unsigned comment added by Tgiesler (talkcontribs) 20:47, 10 January 2012 (UTC)

Done! Thanks! --Stone (talk) 23:39, 10 January 2012 (UTC)

Sodium-collecting butterflies[edit]

Is that going to get included in the article? See this link, which even gives three papers to reference. Double sharp (talk) 03:57, 13 May 2012 (UTC)

Commercial Production Section error[edit]

From the article: "Downs Cell in which the NaCl is mixed with calcium chloride to lower the melting point below 700 °C. As calcium is less electropositive than sodium, no calcium will be formed at the anode. This method is less expensive than the previous Castner process of electrolyzing sodium hydroxide."

Two problems -

1. Reactive metal production is at the cathode, not the anode. Chlorine is produced on the anode.

2. Calcium is not the thermodynamically favored product; however, it is still produced (at the cathode). This requires a post production filtration and will result in trace calcium impurity in the finished sodium product.

A more correct statement for the article is: "Downs Cell in which the NaCl is mixed with calcium chloride to lower the melting point below 700 °C. As calcium is less electropositive than sodium, less calcium will be co-produced at the cathode. Despite post production filtration to reduce the calcium concentration to commercially acceptable level, this method is less expensive than the previous Castner process of electrolyzing sodium hydroxide." — Preceding unsigned comment added by Darkmatterguy (talkcontribs) 02:23, 25 November 2012 (UTC)

Burning[edit]

"Sodium will also burn violently when heated in air." - links as a cite to some sales site for metals. No mention on there that I can see of sodium burning violently in air. Almost just seems like an ad link. Contrast that to: http://www.theodoregray.com/PeriodicTable/Stories/011.2/ where he has a video of some sodium he ignited w/ the help of a blowtorch. "In this video we used a propane torch to light about 10 grams of it in a bowl, to see how it would burn. It burns sort of like magnesium, but easier to light. Sodium burning in air is very gentle, slow, controlled."

So, yeah, question the fact. Wonder if it is just ad link spam. — Preceding unsigned comment added by 68.50.78.21 (talkcontribs) 15:18, 25 January 2013 (UTC)

I agree that the claim is questionable and not supported by the cited reference so I have removed the statement. Thanks for catching the problem and reporting it here. If you would like to add a different statement based on the theodoregray.com reference, please feel free to do so. -- Ed (Edgar181) 15:18, 25 January 2013 (UTC)

Cool. Thanks. As for adding references. Well, this is a semi-protected article, sooo, would have to register which, I'm disinclined to do, frankly. I like the fact that wikipedia allows anyone to edit it, and apart from occasional pain in attempting to correct a misleading image or two (there's still one or two of those I made little progress in), I'll just stick w/ my boring old IP. Feel free to add the cite to Theodore's site yourself tho :) — Preceding unsigned comment added by 68.50.78.21 (talk) 18:09, 28 January 2013 (UTC)

Clarification[edit]

Current text on physical properties:

Sodium at standard temperature and pressure is a soft metal that can be readily cut with a knife and is a good conductor of electricity. Freshly exposed, sodium has a bright, silvery luster that rapidly tarnishes, forming a white coating of sodium hydroxide and sodium carbonate. These properties[which?] change at elevated pressures: at 1.5 Mbar, the color[clarification needed] changes to black, then to red transparent at 1.9 Mbar, and finally clear transparent at 3 Mbar. All of these allotropes are insulators and electrides.[3]

The properties that change with pressure are the ones in the first sentence, not the second. Also, tarnishing in air is a chemical property, not a physical property. I suggest the following revision:

Sodium at standard temperature and pressure is a soft, silvery metal that can be readily cut with a knife, and is a good conductor of electricity. These properties change dramatically at elevated pressures: at 1.5 Mbar, the color changes from silvery metallic to black; at 1.9 Mbar the material becomes transparent, with a red color; and at 3 Mbar sodium is a clear and transparent solid. All of these high-pressure allotropes are insulators and electrides.[3]

When freshly cut, sodium has a bright, silvery luster. If exposed to air, the surface rapidly tarnishes, darkening at first and then forming a white coating of sodium hydroxide and sodium carbonate.

68.173.52.158 (talk) 11:42, 7 April 2014 (UTC)

Thanks. I have changed the text as you proposed, but moved the second paragraph to chemical properties. Materialscientist (talk) 11:55, 7 April 2014 (UTC)

Etymology of symbol Na[edit]

No such word as natrium in Latin but nitrum exists used in reference to soda and natron, the latter ultimately from the Greek nitron. Thus the symbol Na more likely to have an association with natron else it would have been Ni, if nickel had not claimed it first!

Apparently the misattribution dates back to the 1930s according to John Emsley, author of Nature's Building Blocks where he had relied on more recent source material. Latin was not unknown to scholars and scientists in the mid 20th century so why the writers of texts did not check their dictionaries is beyond me - it was my first action on seeing natrium which seemed a most unlikely construction.

As this would not be a simple edit, I leave it to the writer of the article on how best to tackle such a deeply entrenched error.

Chrysippo (talk) 09:17, 20 May 2014 (UTC)

Max burning temp, molar mass[edit]

I removed from infobox sodium: |Max burning temp=1003 K and |molar mass=22.9898g/mol. Not used in infobox element (do not show). -DePiep (talk) 15:36, 8 July 2014 (UTC)

Volume of UL of NaCl[edit]

I've added 2.7 ml of NaCl as the volume-equivalent of 2.3g of Na (UL), and changed this to half a US teaspoon (was 1 teaspoon). 1g Na->NaCl is (58.443/23)g = 2.541g, NaCl density is 2.16 g/ml. CS Miller (talk) 12:46, 31 October 2014 (UTC)