Talk:Carbon/Archive 2

Archive 1

Archive 2

atomic weight of carbon

is the atomic weight correct? according to IUPAC is should be [12.0096; 12.0116] http://iupac.org/publications/pac/pdf/2011/pdf/8302x0359.pdf — Preceding unsigned comment added by 203.22.239.98 (talk) 21:57, 10 December 2012 (UTC)

Talk!

Resolved

 – "Case Closed: [first item -- typo]"

"thermodinamicaly" is a typo. Can somebody please fix it? 64.139.4.126 20:34, 30 November 2007 (UTC)

"In German and Dutch, the names for carbon are Kohlenstoff and koolstof respectively, both literally meaning "coal-stuff"."

For the dutch it is a wrong translation. "Stof" rather means (solid) substance than stuff. like a liquid is being called: "Vloeistof", a 'flowing substance'.

Why isn't lampblack/soot/charcoal counted as an allotropic form of carbon? It is a form that is not diamond, graphite or a fullerene. Of course, it isn't crystalline, but that's not a requirement of being an allotrope.

--user:jaknouse

Aren't they just graphite with impurities? -- Tarquin 11:04 Jan 22, 2003 (UTC)

Yes, it's just a mixture of several different allotropes.- (User) WolfKeeper (Talk) 06:00, 2 December 2007 (UTC)

Does anyone know if carbon nanotubes are considered an allotrope or if they are just a subset of buckyballs? Iammaxus 03:34, 23 Dec 2003 (UTC)

All fullerenes. --mav

All allotropes, by definition.- (User) WolfKeeper (Talk) 06:00, 2 December 2007 (UTC)

The Carbon Cycle

Carbon - in the form of differnet kinds of carbon-containing molecules - moves through an endless cycle. These are the stages of the carbon cycle. It begins when plants and algae remove carbon from the environment during photosynthesis. This carbon returns to the atmosphere via several carbon-cycle pathways.

A) Air contains carbon in the form of carbon dioxide gas. Plants and algae use carbon dioxide to make sugars, which are energy-rich, carbon-containing compounds.

B) Organisms break down sugar molecules me by plants and algae to obtain energy for life and growth. Carbon dioxide is released as a waste.

C) Burning fossil fuels and wood releases carbon dioxide into the atmosphere.

D) When organisms die, their carbon-containing molecules become part of the soil. The molecules are broken down by fungi, bacteria, and other decomposers. During this decay process, carbon dioxide is released into the air.

E) Under certain conditions, the remains of some dead organisms may gradually be changed into fossil fuels such as coal, oil, and gas. These carbon compounds are energy rich.

Graphene

Perhaps this should mention graphene (a single layer of carbon atoms) or reference the graphene page 211.30.190.160 10:35, 14 June 2007 (UTC)

Melting and boiling points?

The article currently claims that carbon sublimes instead of melting and also gives melting and boiling points. Clearly some information is missing. --Andrew 03:58, Apr 13, 2005 (UTC)

Missing... right now I'm having too much of it. I'm not an expert, but I've done a search for a phase diagram and adapted one for the article from a source that appears to know what they're talking about—particularly because it mostly contains ranges and estimates, not concrete numbers. Those seem to be a little more tricky:

The CRC handbook 84th ed. gives:

• For graphite a sublimation point of 3825 °C.
• For diamond a melting point of 4440 °C at 12.4 GPa.
• For graphite a triple point at 4489 °C and 10.3 MPa.

And in the elements section:

• For carbon a graphite-liquid-gas triple point of "4492°C at a pressure of 101.325 kPa" ?!, and it sublimes at 3642 °C.

According to Amazon.com's search inside this book, the "4492°C at a pressure of 101.325 kPa" also is in the 85th ed.
According to [1], the CRC 78th ed. apparently gave here:

• For carbon a melting point of ~3550 °C.
• Graphite sublimes at 3825 °C;
• A graphite-liquid-gas triple point at 4492 °C and 10.3 MPa
• A graphite-diamond-liquid triple point at (3830-3930) °C and 12-13 GPa

Lange's handbook, 15th ed. gives:

• For diamond a boiling point of 3930 °C.
• For diamond a melting point of 3500 °C at 63.5 atm.
• And graphite sublimates at (3915–4020) °C.

Huh.

I've put melting point="triple point, ca. 10 MPa<br />and (4300–4700) K" (from the diagram source), and boiling point="subl. about 4000 K" into the article, until somebody finds better data. Femto 12:28, 16 Apr 2005 (UTC)

Thanks! Wow. --Andrew 22:30, Apr 16, 2005 (UTC)

This is a disaster. The melting point and boiling points should be removed from the elements box. This information should be included as a separate paragraph in the entry, or as a separate entry into the mp and bp of carbon. What is in the element box is essentially useless with out the information above. I had edited it and then came to say something here and then decided to let someone else deal with it. Vargob 17:47, 21 February 2007 (UTC)

I agree this is a mess. As it is now, it makes it seem like the melting point is a higher temperature than its boiling point. This makes no sense at all. --Rkelly74 02:16, 23 October 2007 (UTC)

Big lumps of graphite

THe article doent seem to say where the big blocks of graphite (used in nuclear reactors) come from. Are they synthesised, or dug out of the ground?--Light current 10:44, 28 June 2006 (UTC)

They are always synthesized or purified to some degree and recompressed, since natural graphite always has too much boron and other impurities to be a good moderator. This was a key insight of Szilard which made the Chicago first atomic reactor possible. The Germans never did realize it during the war. SBHarris 01:45, 26 April 2007 (UTC)

History of Carbon is wrong.

According to http://www.pnas.org/cgi/reprint/0510489103v1, and http://www-phys.llnl.gov/pdf/1031204.pdf. Don't get me wrong I beleave the charcoal part should be left in.

"Elemental carbon has been known since prehistory,
and diamond is thought to have been first mined in India 2,000 years ago,
although recent archaeological discoveries point at the possible existence
of utensils made of diamond in China as early as 4,000 before Christ."

- Hamster2.0 04:48, 3 May 2007 (UTC)

I agree with this. Carbon does come in the forms of diamond, graphite and charcoal. I don't have any sources to back this up, but this is true. Charcoal is usually counted as not a form, but it is. Just one that is never overlooked. ☺Efansay^T/_C☺ 06:49, 16 June 2007 (UTC)

Boiling and Melting point are wrong

Someone put (?) question marks around it, it´s better to have nothing at all than erroneous facts.. —Preceding unsigned comment added by 89.54.36.239 (talk) 06:57, 9 September 2007 (UTC)

Finally, hopefully resolved after nearly 2 years of standstill with wrong data. :-( Unbelievable why noone else did this. Regards, Achim1999 (talk) 12:49, 25 July 2009 (UTC)

Carbon

The Carbon article has been nominated for the Wikipedia:Article Collaboration and Improvement Drive. Nergaal (talk) 20:25, 20 November 2007 (UTC)

I found melting points

Carbon =(diamond) C 3550 Carbon =(graphite) C 3675 Carbon =(amorphous) C 3675 —Preceding unsigned comment added by 65.92.202.105 (talk) 23:42, 5 December 2007 (UTC)

any reference? Nergaal (talk) 00:36, 6 December 2007 (UTC)

Abundance of carbon mineral

The following statement is provided unreferenced and I could find nothing to confirm it.

Coal is the main source of carbon in mineral form, containing up to 86% of carbon in anthracite.

I'm not sure the statement is correct. I believe there are more abundant carbonates in the Earth's crust, for example, which is the second most abundate mineral group after the silicates—especially calcite and dolomite. (Although anthracite is probably one of the most carbon-rich minerals.) This change was added March 28, 2007 by User:Freecat. — RJH (talk) 20:59, 21 November 2007 (UTC)

While carbonates contain carbon, they are probably not the main [practical] sources of [elemental] carbon. As an analogy, think of the statement "air is the main source of [elemental] oxygen", which is true, despite the fact that most oxygen on earth is bound on minerals or water. --Itub (talk) 13:27, 6 December 2007 (UTC)

The "practical" source of CO2 gas and dry ice is not the air directly, but the fermentation of sugar to make alcohol. One might also reflect on the fact that the lime that goes into portland cement is produced by driving CO2 from limestone back into the atmosphere (from whence it once came) using the combustion of fossil fuels as energy source - resulting in a very high carbon footprint, if practicality is the issue herePlantsurfer (talk) 14:45, 6 December 2007 (UTC)

I thought we were talking about carbon, not carbon dioxide. --Itub (talk) 17:05, 6 December 2007 (UTC)

reference for infobox

I found this great website and I wanted to reference stuff in the infobox. Unfortunatelly I screw up entries.Can someone else do it instead? Thanks! Nergaal (talk) 22:54, 7 December 2007 (UTC)

Abundance of carbon in Earth's crust

I removed the sentence regarding carbon as the sixth most abundant element in the earth's crust because it had a "citation needed" note and upon googling it doesn't even show up in the top 10 most abundant elements (by weight).[2] --Wizard191 (talk) 04:36, 5 January 2008 (UTC)

South Korea production

There's a wrong sentence about natural graphite. In South Korea, most (more than 99%) of graphite is imported. —Preceding unsigned comment added by 150.150.114.124 (talk) 02:25, 18 April 2008 (UTC)

According to this USGS report, North Korea was the 4th largest producer of graphite in the world, after China, India, and Brazil. I'll change the article to reflect this. Cheers Geologyguy (talk) 02:47, 18 April 2008 (UTC)

Semi-protect the page?

this article recieves a large amount of vandalizations from unregistered users. It might be a good idea to semi-protect it.Nergaal (talk) 01:55, 26 January 2008 (UTC)

Diamond decay

I've heard various sources say that diamonds decay into graphite at standard conditions, and others say that they don't. Can anyone find a source that gives the actual rate of decay? Presumably it can be calculated by knowing the activation energy and assuming a probability distribution for heat energy available to individual atoms. -- Beland (talk) 19:09, 11 June 2008 (UTC)

It depends on the value of the activation energy. I don't think it is known accurately, but I've seen some estimates in the range of 70-100 kcal/mol. That is huge. At room temperature, it corresponds to a half-life that is orders of magnitude longer than the age of the universe. At 1000 degrees you might have a reasonable rate. --Itub (talk) 06:01, 12 June 2008 (UTC)

Broken Reference

I removed a broken reference named "hershey" from the article. Possibly the ref was broken due to vandalism but as far as I could tell it was never working in the first place. --Megaboz (talk) 18:25, 9 September 2008 (UTC)

Conflicting abundance numbers

There are several conflicting numbers in the abundance section about hydrocarbons. At first it talks about reserves of 900GT, then, in the next paragraph, it talks about 4000GT of carbon suitable as fuel. And the the little floating box at the side talks about 13.2 x 10^6 GT of Carbon in the form organic compounds in the upper crust. This is totally confusing and needs to be corrected, explained better, or removed. --Dio1982 (talk) 15:16, 23 October 2008 (UTC)

Melting Point/Boiling point

I have been doing some research and found that 3652degC is the melting point of Carbon and that 4827degC is the boiling point. I don't see these figures mentioned anywhere in the article so I'm wondering whether they are accurate or not. The same website stated that graphite had a melting point of 3500degC so this could also be mentioned if it is correct. I have listed my reference here: [3] Bonzostar (talk) 17:56, 6 November 2008 (UTC)

Where the hell have the melting point and boiling point went!!!

Dannyboy1209 (talk) 15:34, 22 February 2011 (UTC)

Gone to hell no doubt... Please see the discussion above entitled "Melting and boiling points?" Vsmith (talk) 16:04, 22 February 2011 (UTC)

General comment about elemental photos

I'm wondering out loud why many of the photos of samples of major elements in the infoboxes seem to be grainy, badly lit, low resolution images that don't really give much of an idea of what it really looks like close up. Is anyone with access to elemental samples able to take some better photos? (Apologies to user RTC who at least has taken the trouble to upload the current ones). --CharlesC (talk) 23:56, 23 January 2009 (UTC)

I have a set o' elements and took a photo of one for the yttrium article. But I'd like to wait until I get a new camera or at least a much better macro lens before I start up a production line; just to make sure I get better resolution and don't have to GIMP the image as much. --mav (talk) 23:39, 7 March 2009 (UTC)

Standard Atomic Weight is wrong

The standard atomic weight shown is wrong: should be 12.01 approximately. 6 is the element number not the standard atomic weight. —Preceding unsigned comment added by Arthur Merlin (talk • contribs) 00:21, 20 March 2009 (UTC)

It's actually 12.0107, but I think I'm nitpicking here. --116.14.27.127 (talk) 08:46, 3 June 2009 (UTC)

The density of Carbon is incorrect.

The density of Carbon, at 0°C and 1atm, is stated incorrectly to be 2.267 g/L (that density is extremely low, meaning diamonds would float on water for example).

At 0°C and 1 atm, pure Carbon can exist in three forms:

1) Graphite, specific gravity: 2.26

2) Diamond, specific gravity: 3.51

3) Amorphous, bulk density: 1.8-2.1 g/cm³

From the Chemical Rubber Company Handbook of Chemistry and Physics, 59th Edition, CRC Press, Inc, 1979.

Harting (talk) 11:20, 24 March 2009 (UTC)

Correct, so why not modify the article accordingly. Plantsurfer (talk) 17:51, 24 March 2009 (UTC)

Sadly the article is semi-protected and I have not been around long enough to be allowed to edit it. Harting (talk) 16:31, 26 March 2009 (UTC)

The data is actually housed at {{infobox carbon}}, which is not protected from editing. I made the suggested changes there. Please check me, to be sure that it is correct now. ChemNerd (talk) 19:58, 26 March 2009 (UTC)

OK, but the value for diamond was wrong, and I have edited it to list the allotropes in ascending order of their density. Plantsurfer (talk) 20:30, 26 March 2009 (UTC)

I've changed the density of graphite to the exact reported in the source book. It's quite old, but then densities of compounds don't exactly change. Harting (talk) 14:31, 27 March 2009 (UTC)

Specifying a density for amorphous carbon is very misleading. Depending on the sp2:sp3 fraction it can vary greatly. Diamondlike amorphous carbon can be grown by ion beam deposition with densities reaching 3g/cm³. Specifying a range would thus be more appropriate. --Dschwen 15:42, 27 March 2009 (UTC)

You are right. It is usually quoted as a range. The lowest number I've ever come across is 1.8. So a range of 1.8 to 3 seems to be at least achievable. As it isn't a physical constant, maybe it should be omitted from the info box.Harting (talk) 12:53, 30 March 2009 (UTC)

For the time being I've changed the number to the range that is quoted in the source text. If someone has a reference to a more modern up-date reference then I'd gladly change it again. Harting (talk) 13:13, 31 March 2009 (UTC)

Life on Earth

The article states:

Carbon compounds form the basis of all life on Earth...

Huh? According to Wikipedia's article, we don't even have a good definition of life! Even if we did, it's not entirely clear (at least from what I've read) that we know about all life on Earth. Brian Jason Drake 13:09, 24 April 2009 (UTC)

I shall reply to that on User_talk:Brianjd where it belongs.NIMSoffice (talk) 23:20, 24 April 2009 (UTC)

Though I disagree that it belongs there, I have responded there. Brian Jason Drake 02:14, 30 April 2009 (UTC)

I must agree, per WP:TALK, such a discussion is perfectly appropriate here. User talk is for one-on-one discussions. This however, is a discussion about the article, which belongs here so others can view it and participate in the discussion.

The claim of carbon forming the basis for all life on Earth should be properly sourced. We could also soften the claim by saying "all known life", just in case there are any silicon based lifeforms hiding somewhere we haven't found. But I wouldn't call the claim dubious in it's current form. While there are things we are not sure about, we do not have reasonable doubt regarding the claim. -Verdatum (talk) 17:04, 4 May 2009 (UTC)

I softened the statement in the article (it is minor, and can even be deleted). IMHO the discussion belongs to the articles on life, not on carbon. NIMSoffice (talk) 00:02, 5 May 2009 (UTC)

Shouldn't Carbon also be in Category:Biology and pharmacology of chemical elements ? Eldin raigmore (talk) 18:16, 16 May 2009 (UTC)

Eldin, please be bold. If you feel it should be in that category, why not insert it yourself? Double sharp (talk) 08:49, 3 June 2009 (UTC)

Abundance of Carbon

"Carbon is one of the least abundant elements in the Earth's crust, but the fourth most abundant element in the universe by mass after hydrogen, helium, and oxygen."

According to the linked table, Carbon is the 15th most abundant element among the 82 stable or semi-stable in the earth's crust, not one of the least abundant. Indeed, it ranks above sulfur and chlorine, which are pretty abundant.--Syd Henderson (talk) 05:31, 18 September 2009 (UTC)

Thanks. Fixed that. Materialscientist (talk) 01:12, 16 October 2009 (UTC)

Characteristics/Extremes

The first section ends with “The system of carbon allotropes spans a range of extremes:” followed by a table comparing diamond and graphite. One of the entries is “Diamond crystallizes in the cubic system. Graphite crystallizes in the hexagonal system.” I agree that's a difference, but I don't see how it's “two extremes”. bogdanb (talk) 18:22, 20 January 2010 (UTC)

"Extremes" here refers to other properties, certainly not to the crystal symmetry, and is simply an emphatic word, which can be replaced. Materialscientist (talk) 22:49, 20 January 2010 (UTC)

ancient charcoal

surely carbon in the form of charcoal was known before the time of the Romans?(history section)195.188.41.154 (talk) 11:16, 4 February 2010 (UTC)

Timeline of chemical elements discoveries says around 3700 BC "Earliest known use of charcoal for the reduction of copper, zinc and tin ores in the manufacture of bronze, by the Egyptians and Sumerians." Charcoal can exist in nature and could be used by the earliest human civilizations if discovered. It seems charcoal wasn't made until around Roman times(earliest known manufacture). JTTyler (talk) 07:52, 26 March 2010 (UTC)

Carbon Used in Steel

I believe that this article deserves a small section on the use of carbon is production of steel; the identification of carbon and its use in steel was a major industrial and scientific achievement. For example, samurai swords were produced by carbon refined from river sediments. This and other examples of carbon refinement and application lead to a metal that we now use in, "buildings, infrastructure, tools, ships,automobiles, machines, appliances, and weapons." (See Steel) This discovery of carbon for steel could even be considered more significant than the demonstration of steel production by René de Réaumur in 1722, especially because earlier steel use has occurred during the 4th century BC (while steelwork itself dates back nearly four thousand years ago). (See http://en.wikipedia.org/wiki/Steel#History_of_steelmaking)

If these discoveries are insignificant or irrelevant, I believe that a link at least should be provided in the History section of the article for Carbon.

Adam zappul (talk) 05:31, 6 June 2010 (UTC)

Carbon - largest number of compounds

The article states that carbon produces more compounds than any other element and cites the millions of organic compounds in evidence. But every organic compound also contains hydrogen So the "accolade" for most compounds must surely be whichever of hydrogen and carbon produces the most inorganic compounds without the other being present. Are there more hydrides and inorganic acids than there are carbides and carbonates? I don't know the answer!

Should it be deemed that Carbon does indeed have more compounds than hydrogen then the evidence cited needs to be changed to reflect this. Eccleshill (talk) 08:39, 15 July 2010 (UTC)

Hydrogen is not the basic structural element of hydrogen-containing compounds. Materialscientist (talk) 08:52, 15 July 2010 (UTC)

That is not the issue - the issue is the number of compounds that are formed not the function of the element in those compounds. Eccleshill (talk) 09:12, 15 July 2010 (UTC)

It is the issue - hydrogen does not form those compounds, it is part of these compounds. Materialscientist (talk) 09:16, 15 July 2010 (UTC)

Perhaps we are at the level of linguistic semantics! A compound must by definition contain more than 1 element; carbon cannot form "compounds" alone; it forms compounds with hydrogen; hydrogen forms compounds with carbon. The compounds are formed from carbon and hydrogen therefore surely they form compounds in equal number. Eccleshill (talk) 09:38, 15 July 2010 (UTC)

In Our Time

The BBC programme In Our Time presented by Melvyn Bragg has an episode which may be about this subject (if not moving this note to the appropriate talk page earns cookies). You can add it to "External links" by pasting * {{In Our Time|Carbon|p003c1cj}}. Rich Farmbrough, 03:01, 16 September 2010 (UTC).

Incremental Alpha particle mass value calculations

If a regression analysis of incremental alpha particle mass increases to the atomic structure is carried out and then used to estimate the fit of the reported AMU mass values to the best fit line, the reported value of 12.0000 for EE6C12 is noted to fall bellow the best fit line (third order) by more than the EE8O16 value. Could this indicate a bias such that the estimated AMU values of the heavier elements is overestimated?WFPM (talk) 15:41, 22 January 2011 (UTC)

Small glitch

Something has gone wrong here:

"In 1779, Carl Wilhelm Scheele showed that graphite, which had been thought of as a form of lead, was instead a type of carbon. In 1786, the French scientists Claude Louis Berthollet, Gaspard Monge and C. A. Vandermonde then showed that this substance was carbon." —Preceding unsigned comment added by 86.177.106.149 (talk) 01:52, 4 May 2011 (UTC)

Yes. The latter group of chemists burned graphite in oxygen and found that it was MOSTLY the oxide of a new element that they called "carbon" (Scheele had done the same by oxidizing graphite to CO2 in nitric acid, but he called CO2 aereal acid and was still working in the phlogiston theory so did not really regard it as an oxide of anything primary). Both groups found some residual iron, but the Frenchmen thought there was enough to think graphite a carbon-iron compound. Scheele did not make that mistake. Lavoisier had found diamond to contain nothing that didn't produce CO2, so he accepted "carbon" as the name of the element being oxidized when burned in oxygen. SBHarris 03:56, 4 May 2011 (UTC)

Application

More applications should be listed...such as the use of carbon filament for light historically.Smallman12q (talk) 20:39, 27 June 2011 (UTC)

Also...there's also no article for a astatine carbon bond...which is the subject of some research.Smallman12q (talk) 23:53, 11 July 2011 (UTC)

carbon platinum only academic

maybe I misread the very nice periodic table, but I saw Carbon platinum as of academic interest only. I may be wrong, but arent compounds like cisplatin of importance, and don't they have carbon pt bonds ? — Preceding unsigned comment added by 68.236.121.54 (talk) 14:22, 28 October 2011 (UTC)

Cisplatin is an important compound, but it doesn't contain any carbon atoms, much less C–Pt bonds. Double sharp (talk) 03:14, 12 June 2012 (UTC)

Liquid

Is it possible to create liquid carbon? 174.20.186.136 (talk) 01:19, 16 July 2011 (UTC)

I don't see why not. You just need the right temperature and pressure. Lanthanum-138 (talk) 08:59, 6 August 2011 (UTC)

History in the infobox

I'm working on entering the discovery details into the infoboxes of all the elements. I was planning on entering the following:

Discovery: Antoine Lavoisier (1789) 
Earliest known use: Egyptians & Sumarians (3750 BC)

Is the meaning understood here? That it was 'discovered' when it was recorded as an element? Or does it look paradoxical to have the earliest known use before it was 'discovered?Nozzleberry (talk) 21:49, 26 June 2012 (UTC)

Diamond Production Map Flawed

The modifications that are made to the map of global diamond production, have made the Russian production (which is the biggest in the world) invisible!

Must be reverted to the previous version of the map — Preceding unsigned comment added by 83.183.113.247 (talk) 19:31, 22 August 2012 (UTC)

Reverted, thanks. Materialscientist (talk) 22:35, 22 August 2012 (UTC)

Edit request on 6 November 2012

IMPRECISION:...diamond has the highest thermal conductivity of all known materials.

►...diamond, carbon nanotube and graphene have the highest thermal conductivity of all known materials. 84.221.87.54 (talk) 00:22, 6 November 2012 (UTC)

Changed, thanks. Materialscientist (talk) 00:32, 6 November 2012 (UTC)

Edit request on 26 November 2012

I am a Phd student in chemistry and would like to make minor changes to this article as well as others on the subject, I intend to document all changes with peer-reviewed, edited references and am happy to defend why I feel these changes would be necessary. Spire music (talk) 23:20, 26 November 2012 (UTC)

Sorry, but you need to suggest a specific edit. See your talk page. Vsmith (talk) 23:58, 26 November 2012 (UTC)

Edit request on 2 April 2013

Under precautions section.

Grammar error in: "carbon nanoparticles are a deadly toxins to"

Remove the "s" at the end of "toxins" or remove the "a" in front of "deadly". Idenshi (talk) 16:18, 2 April 2013 (UTC)

Done (more or less). I also split up the run-on sentence and changed "toxins" to "toxic", since the construction "toxins to" seemed awkward. Rivertorch (talk) 16:57, 2 April 2013 (UTC)

Semi-protected edit request on 28 January 2014

The article does not throw enough light on extra terrestrial occurrence of carbon. What I want to focus on is that carbon-rich asteroids are relatively preponderant in the outer parts of the asteroid belt in our solar system. Please add this information to this page. Sometimes, meteorites originating from that part of our solar system may have high amount of carbon. This information can help us to understand the presence of carbon in planets like Mars and Venus, which are nearer to the asteroid belt. However, carbonaceous asteroids have yet not been sampled directly by scientists. These asteroids can help in space-based carbon mining; however this seems to be only a scientific but fictitious possiblity with our present day technical know-how. For details, refer to Charles R. Nichols's article at http://www.uapress.arizona.edu/onlinebks/ResourcesNearEarthSpace/resources21.pdf Arghyan Opinions (talk) 07:13, 28 January 2014 (UTC) Arghya Ray

Done at bottom of "Occurrence" Dmelc9 (talk) 18:33, 31 January 2014 (UTC)

Semi-protected edit request on 1 March 2014

Please change '6.155 (diamond)\n8.517 (graphite) J·mol−1·K−1' in Molar Capacity with 'Diamond: 6.155 J·mol−1·K−1\nGraphite: 8.517 J·mol−1·K−1', because current formatting is not correct. Lubomir Kucera (talk) 17:22, 1 March 2014 (UTC)

Not done: please establish a consensus for this alteration before using the {{edit semi-protected}} template. It's been that way for well over two years now and I do not see any requests to change it before this. Please either show where in the MOS the formating is defined that current usage is incorrect. Thanks. — {{U|Technical 13}} ^{(t • e • c)} 17:39, 1 March 2014 (UTC)

Greek name origin

I have a very small point which I think should still be changed: the Greek word γραφω means "I write". "to write" like the article says would be "γραφειν". I don't care which form we choose but the English translation should match the Greek.Sbreheny (talk) 17:25, 10 April 2014 (UTC)

User talk:Kwamikagami#Carbon says that you are right, but he didn't select one, so go ahead and choose the form you think makes the most sense. CorinneSD (talk) 19:38, 8 June 2014 (UTC)

Merge from carbonaceous

I propose converting carbonaceous into a disambiguation page, listing what is currently in its See also section (i.e. this). "Carbonaceous" doesn't seem to me like an important or prominent term, and the article is completely unreferenced. Adabow (talk) 03:26, 25 June 2014 (UTC)

OPPOSE MERGE There are many odd uses of "carbonaceous" in geology and cosmochemistry. They would clutter the carbon article if we stuck them in here, and deserve their own article. I've already added a dictionary reference and improved the carbonaceous article with that reference, and there are many more to be easily added from the carbonaceous chondrite article. This word is exactly the sort of term for which Wikipedia is useful-- too widely used to be a good dictionary-only term, and with most of its uses highly specialized and technical, which need explaining. SBHarris 01:46, 27 June 2014 (UTC)

Allotropes we suck & kiss

I suggest we use two separate & good pictures of the most famous allotropes we know. The allotrope we sucked on in childhood, and the allotrope we kiss when grown up.

(In {{Infobox carbon}}, we can use |image 2=, and drop the spectre. No need for the measurement to be in view. There is no alpha/beta naming?). -DePiep (talk) 17:48, 17 July 2014 (UTC)

I don't think there is alpha/beta naming for C allotropes: allotropes of carbon does not mention it. There is α- (hexagonal) and β- (rhombohedral) graphite, though. I suspect the reason is that α- and β-carbon already have a more common meaning in chemistry. Double sharp (talk) 23:58, 17 July 2014 (UTC)

I admit, this current picture has very high quality, and it's free. So my point is less relevant. -DePiep (talk) 22:08, 10 August 2014 (UTC)

Semi-protected edit request on 11 October 2015

Picture caption reads "...phrase diagram..." Should be "...phase diagram..." 142.129.121.165 (talk) 14:31, 11 October 2015 (UTC)

If you mean the one in the Characteristics section, it looks like it's already phase diagram. Cannolis (talk) 14:39, 11 October 2015 (UTC)

In order to be available for formation of life as we know it

Originally, the statement was oddly phrased on this page, like it was lifted from a text on Intelligent Design:

• In order to be available for formation of life as we know it, this carbon must then later be scattered into space as dust, in supernova explosions, as part of the material which later forms second or third-generation star systems which have planets accreted from such dust.

Awkward. I reworded it, but still not happy. I notice that Plantsurfer (talk · contribs) has already changed it more, but I think it needs a different approach. Please consider this:

• According to theory, carbon is formed in the interiors of stars in the horizontal branch by the transformation of three helium nuclei.[64] When the stars die in supernova explosions, the carbon is scattered into space as dust. This dust becomes component material for the formation of second or third-generation star systems which have planets accreted.[41][65] The Solar System is one such third-generation star system with an abundance of carbon and life as we know it.

Please comment. Grammar'sLittleHelper (talk) 00:18, 6 April 2016 (UTC)

valency

What is the valency of carbon Sandeep xettri (talk) 06:20, 3 October 2016 (UTC)

Four. There are naturally exceptions, but to a first approximation, always four. Double sharp (talk) 03:37, 8 October 2016 (UTC)

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Typo: "Isotopess"

Third sentence: Three -"isotopess"- occur naturally, 12C and 13C being stable, while 14C is a radioactive isotope, decaying with a half-life of about 5,730 years. ASteveMt (talk) 17:26, 7 January 2017 (UTC)

Fixed. Double sharp (talk) 03:54, 8 January 2017 (UTC)

misprint

you've got a misprint in the infobox of this "good article". The standard atomic weight of carbon is 12.0096 to 12.0116 not 12.096 to 12.116

86.140.78.188 (talk) 02:45, 13 April 2017 (UTC)

Fixed. Double sharp (talk) 09:55, 13 April 2017 (UTC)

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Improper "(questionable)".

For some odd reason, the existence of lonsdaleite is followed by the note "(questionable)", although nothing in the literature, including here on Wikipedia, presents anything to indicate that it is "questionable" in any scientific sense.

On the contrary: other articles here state that it is not only unequivocally found in asteroids, but that it has been synthesized in the laboratory as well.

I will remove the "(questionable)" part of that paragraph. — Preceding unsigned comment added by Jane Q. Public (talk • contribs) 06:01, 20 January 2018 (UTC)

Semi-protected edit request on 25 January 2019

규호 ㅏㅌ츠ㅑㅓㅕ류오ㅜ ㄹ파ㅐㄴㄷㅇㄹ ㅏ애츄ㅗ점나ㅐㅇ츄ㅙㅁ널아ㅡㅐㅈㄷㄴ옾류 우처ㅑㅕ몬ㅋ — Preceding unsigned comment added by Songtaeuk (talk • contribs) 03:40, 25 January 2019 (UTC)

This seems to be meaningless and probably a test edit. Graeme Bartlett (talk) 06:36, 25 January 2019 (UTC)

Melting, boiling and triple point

I want to change "At atmospheric pressure it has no melting point, as its triple point is at 10.8±0.2 MPa and 4,600 ± 300 K (4,330 ± 300 °C; 7,820 ± 540 °F),[2][3] so it sublimes at about 3,900 K (3,630 °C; 6,560 °F).[20][21]" to "Very many different values can be found in the literature for the melting, boiling, sublimation and triple point temperatures of carbon. The best that can be said is that at standard pressure, the boiling point of carbon is 4,000 ± 250 K (3,730 ± 250 °C; 6,740 ± 400 °F), (reference “E.I. Asinovsky et al. (2002), Fig. 3”) and the melting point, extrapolated down from 80 bars is 4,050 ± 100 K (3,770 ± 100 °C; 6,850 ± 160 °F). So carbon sublimes at atmospheric pressure, but there is some doubt about it. The triple point pressure is definitely less than 80 bars (8 MPa) and is more likely to be near 10 bars (1 MPa). The triple point temperature is 4,050 ± 100 K (3,770 ± 100 °C; 6,850 ± 160 °F)." Mollwollfumble (talk) 05:45, 17 June 2019 (UTC)

Audio version.

Should I add the audio version to the "Carbon" article? And, how do I record and add it? Kuro (talk) 00:45, 9 October 2020 (UTC)

Semi-protected edit request on 20 December 1950

Carbon is currently the 17th most abundant element found on this earth, but in the article due to some problem it is written as 15th. Please correct 116.74.38.204 (talk) 11:21, 20 December 2020 (UTC) 116.74.38.204 (talk) 11:21, 20 December 2020 (UTC)

 Not done: please provide reliable sources that support the change you want to be made. Jack Frost (talk) 11:44, 20 December 2020 (UTC)

Semi-protected edit request on 13 January 2021

change

However, a recent computational study employing density functional theory methods reached the conclusion that as T → 0 K and p → 0 Pa, diamond becomes more stable than graphite by approximately 1.1 kJ/mol.[45]

to

Although a computational study employing density functional theory methods reached the conclusion that as T → 0 K and p → 0 Pa, diamond becomes more stable than graphite by approximately 1.1 kJ/mol , more recent and definitive experimental and computational studies show that graphite is more stable than diamond for T < 400 K, without applied pressure, by 2.7 kJ/mol at T = 0 K and 3.2 kJ/mol at T = 298.15 K . Jzwanzig (talk) 14:56, 13 January 2021 (UTC)

References

 Done Elliot321 (talk | contribs) 22:17, 20 January 2021 (UTC)

Regarding removed text

I just removed the sentence "In July 2020, astronomers reported evidence that carbon was formed mainly in white dwarf stars, particularly those bigger than two solar masses." from the section on Occurrence. This section cited an Inverse article and the journal article that said Inverse article itself cites.

However, the sentence is not supported by the journal article (it essentially parrots the Inverse article, which is a gross misinterpretation).

Most of the carbon in the universe is in white dwarf stars. This is basic knowledge of astrophysics and uncontested. However, this carbon is not relevant to things such as planetary formation and the composition of new stars; it is confined in the white dwarf essentially permanently. Thus, astrophysicists often talk of the sources of carbon in the interstellar medium - i.e., that not locked in remnants. As carbon is only formed in stars, this translates to the various ways that stars can shed material enriched in carbon - the main contributors to this are the stellar wind of dying AGB stars (which will eventually leave behind white dwarfs, but are not yet such), and core-collapse supernovae. White dwarfs can shed material into space via type Ia supernovae; however, this is not thought to be a major contribution to carbon abundance in the ISM.

(In terms of nuclear origin, white dwarfs produce no carbon except a miniscule amount during helium novae. Carbon is created via the triple-alpha process in the cores of AGB stars, red supergiants, and the various higher-mass evolved stars such as LBVs and Wolf-Rayet stars.)

What the paper claims is that AGB stars in a certain range of initial mass (1.6-1.9) have weaker stellar winds than previously thought, and therefore contribute very little carbon to the ISM (as more of it is deposited in the white dwarf remnant). It does not claim that the source of carbon (either in terms of nuclear origin or dispersal into ISM) is white dwarfs.

(As an aside, the mention of "white dwarf stars... bigger than two solar masses" is nonsense. White dwarfs cannot have masses that high, due to the Chandrasekhar limit. The mass of a white dwarf is much lower than the initial mass of the star that produced it; the journal article asserts that stars of initial mass 1.5-2.8 solar masses all leave white dwarfs of masses 0.6-0.75 solar masses, though the dependence is - this is the point of the article - not monotonic.) Magic9mushroom (talk) 12:27, 1 May 2021 (UTC)

With sulfide? what state?

Quote:

with sulfur to form carbon disulfide and with steam in the coal-gas reaction:
C(s) + H2O(g) → CO(g) + H2(g).

There is no sulfur in this reaction. Does anyone know what has happened here?

I believe the problem was that these sulfur and water reactions had been cut off from their subject and verb ("Carbon reacts...") by several intervening sentences, so it didn't seem to make sense in this Old revision of Carbon. I deleted it thinking it was a non-sequitur, and now restored it with repaired grammar. --MadeOfAtoms (talk) 10:35, 15 June 2021 (UTC)

Why are we using (s) and (g) here? This is not interesting in a chemical reaction.

control the carbon content of steel:

Fe3O4 + 4 C(s) → 3 Fe(s) + 4 CO(g)

In this reaction, iron is molten, not solid (s). Fe3O4 does not have (s). I suggest we just drop these phase (state) designations in these equations. This is the first in about 30 pages where they appear. Consensus?

carbon

carbon 27.61.213.169 (talk) 10:31, 31 December 2021 (UTC)

Melting point of diamond

User:Eric Kvaalen, as a complete non-expert I'm a bit confused by the note you added to the phase diagram in the intro, and looking to improve it. Firstly, the link referenced seems to be about the melting point of diamond ("shock-compressed" diamond, whatever that really means), which does not include the melting point of Graphite listed in the table, so this needs to be clarified. Second, is the note saying the upper line between Diamond and Liquid is wrong and should be edited? Is there a pressure-temp phase diagram from the paper that we could include here instead?

Finally, would it be better to include this note in the text, rather than in the figure? Thanks! Cstanford.math (talk) 12:49, 4 October 2021 (UTC)

@Cstanford.math: Hello. Yes, the title of the reference is "Melting temperature of diamond at ultrahigh pressure", because it's looking at the melting point at high pressures where the solid would be diamond. "Shock-compressed" means that they shoot a laser at a small disk of diamond, or actually at a thin coat of aluminum if I remember right on the small disk of diamond, and this causes very rapid ablation of the aluminum, which acts like a rocket engine you could say, causing a shock wave to travel through the carbon. This shock wave causes the carbon to go very briefly to very high temperatures and pressures, and they can actually figure out what the path through T-P space is. I don't know what table you are referring to. It's true that the melting point of diamond (which depends on pressure) is not the same as the melting point of graphite (which also depends on pressure), except at the "triple point" where graphite, diamond, and liquid carbon are all in equilibrium. Yes, the graph is wrong at the upper right. Instead of continuing to curve to the right, it should curve upwards toward higher pressure without ever surpassing 9000 K in temperature. Yes, there is a diagram in the paper, but of course somebody would have to make a copy as an SVG file or whatever. Fortunately the article is open-access. Yes, we could put something in the text, but I thought it was more important to modify the caption because people need to know that the curve is wrong. Anyway, people don't always read the text very carefully. Eric Kvaalen (talk) 09:17, 5 October 2021 (UTC)

That all makes sense, thanks! I clarified the figure caption based on what you wrote here. Mainly, I wasn't sure which part of the phase diagram the caption was correcting, but I think it's clear now. Feel free to improve further. Cstanford.math (talk) 16:39, 5 October 2021 (UTC)

Carbon

How can diamond be created by putting pressure on carbon how is it possible? 147.92.91.58 (talk) 04:06, 23 November 2021 (UTC)