Talk:Covalent bond

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Old talk hidden[edit]

Old comments

'10 Comments[edit]

Anyone in favor of semi-locking this page? Feneeth of Borg / 3of12 21:40, 22 Feb 2010 (EST)

'09 Comments[edit]

an idea: can we please have some examples of covalent bonds eg. the diatomic molecules of gases, water, carbon dioxide —Preceding unsigned comment added by (talk) 06:35, 17 March 2009 (UTC)Reply[reply]

'03 - '04 Comments[edit]

"Atoms tend to share electrons in such a way that their outer electron shells are filled." Isn't that misleading, given that the stable number of 8 electrons is not the maximum number of electrons that can fit in the third shell and beyond?

No, see electron counting.

I just have a question, maybe you all can help me!..What is an example of a Covalent Bond and explain what is happening at the atomic level during bonding?.... im doing a chemisrty paper and that is one of the questions, if you know the answer.. please tell mee!

Ahem...the picture seems to show a CH4 molecule but says "ethene". Don't want to mess with the picture (I'm not great at graphics) but would some other Most Honorable Wikipedian care to look after it? Kosebamse 09:55 Mar 23, 2003 (UTC)

Covalent bonds are more common between non-metals, whereas ionic bonding is more common between two metal atoms or a metal and a non-metal atom.

What would be an example of an ionic bond between two metal atoms? This would require that a metal form an anion. Josh Cherry 22:24, 17 Oct 2003 (UTC)

Yep - I've corrected it.... --Ian 09:34, 29 Jan 2005 (UTC)

==Cis and trans==
Straight- or normal-chain (even-numbered), monoenoic components, i.e. with one double bond, make up a high proportion of the total fatty acids in most natural lipids. Normally the double bond is of the cis- or Z-configuration, although some fatty acids with trans- or E-double bonds are known.

This seems completely out of place to me. I'm tempted to remove it. Josh Cherry 22:31, 17 Oct 2003 (UTC)

I encourage you to indulge yourself, but I do think it would be nice to keep a linked mention of cis and trans in there somehow, because people encounter these terms all the time now with "trans fats" in the news, and so I think even somebody who is just at the stage of learning what a bond is would do well to have the difference between cis and trans included in their curiculum. Most people won't want to go on and delve into an article about IUPAC naming rules or about alkenes, and yet they're liable to encounter "trans fat" and "trans double bond" and wish they knew what it meant. The stuff about lipids belongs in an article about lipids or fats, I think. 168... 00:10, 18 Oct 2003 (UTC)
I've just axed it. This article is about covalent bonding, and that was talking very specifically about the bonding in fatty acids. cis and trans is something much more general than that, I don't think that the description there helped much. Iridium77 13:38, 22 May 2004 (UTC)Reply[reply]

I don't know why this article says that covalent bonding is STRONGER than ionic bonding? This is incorrect... Unless Im mistaken

Covalent bonding is usually stronger than ionic bonding. Iridium77 13:39, 22 May 2004 (UTC)Reply[reply]

Electron Dot Notation[edit]

Does anyone have plans for an Electron Dot Notation article? A seperate, improved article would be useful. It would need step by step instructions, ect. Alternatively, someone could link the Electron Dot Notation page to this one, but that would be slightly inadequate I'd do it myself, but I'm laking in time and skill. Pingveno 04:46, 1 Dec 2003 (UTC)

Such "step by step instructions" is more suitable at wikibooks. --Menchi 04:58, 1 Dec 2003 (UTC)
Does much of anything even exist there? If so, then just link there. Pingveno 05:09, 1 Dec 2003 (UTC)

Also noticed that a page concerning the naming of covalent compounds, and indeed any naming conventions for all of Chemistry, would be extremely useful. Pingveno 05:24, 1 Dec 2003 (UTC)

Covalent radius[edit]

Covalent radius is made a redirect here, but this page does not contain the word "radius". Probably covalent radius should be made into real article, like they have it on other wikipedias: de:Kovalenter Radius, fr:Rayon de covalence and pl:Promień walencyjny, to name a few. --romanm (talk) 21:51, 28 Sep 2004 (UTC)

Nobody complaint, so I at least made a stub instead of redirect. Please see covalent radius and try to improve it. --romanm (talk) 13:49, 17 Oct 2004 (UTC)

Left, right, and up[edit]

The three shared orbitals in a triple bond can be imaged as left, right, and up.

I don't see what this is trying to convey. The two pi bonds are at right angles to each other, looking down the bond axis, and the sigma bond is symmetric about the axis, or straight ahead if you like. Where does "left, right, and up" come from? Which one is the sigma bond? Josh Cherry 03:55, 5 Oct 2004 (UTC)

A correct way to say this would be middle, up and down and left and right, π bonds are "surronding" the σ bond at a straight angle. Orbital hybridisation is one theory that explains this.
A quadruple bond as in C2 would be a σ-bond and three π-bonds. The σ-bond forms directly between the two carbon atoms, but is shunted upwards by the repulsive force of the two π-bonds to the left and right (hence left, right and up). The third π-bond would have to bend all these bonds excessively, leading to instability. I am, however, working on an A-level view of how bonds form, so please correct me if I'm wrong. Thomas Winwood 23:04, 15 Dec 2004 (UTC)
I don't doubt that there would be a steric issue with a fourth bond, but I still don't see the "left, right, and up" in a triple bond. The two π-bonds are at right angles to each other, so "left" and "right" doesn't make sense to me. I don't understand in what sense the σ-bond is "shunted upwards" either; if it's direction is to be called "up" in a triple bond, it's "up" in a single or double bond too. Josh Cherry 23:40, 15 Dec 2004 (UTC)
I really think the reference to a quadruple bond for C2 and Si2 is mistaken, so we should remove it all. C2 is normally described as having a double or maybe triple bond - it isn't explosive, merely unstable. Quadruple and higher bonds get described for esoteric transition metal compounds, but that's it. So, unless someone has good reference sources to show otherwise, I'll chop it soon!--Ian 14:02, 8 Feb 2005 (UTC)

Rotation of double/triple bonds[edit]

I thought that this was relavant to the article, so I put a couple of sentences in on it. I wanted to make sure with someone else on this before I put it in though: Is a triple bond less rigid than a double bond in terms of rotation? I would think so because in a triple bond, the pi orbitals being used are perp. to each other, so when you rotate it, then there will be at least some orbital overlap. Compare that to a double bond where when you rotate it 90 degrees, then there is no pi overlap at all. That's what I seem to remember from gen chem, but I can't find any notes on it or any external refs either.Sareen eng 06:43, 28 July 2005 (UTC)Reply[reply]

Um-- The diagram is BAD considering quantum mechanics. The Bohr model of the atom is dead.

Giant macromolecular covalent vs simple covalent molecular[edit]

Shouldn't this be mentioned somewhere? EvilStorm 15:39, 19 January 2006 (UTC)Reply[reply]

The bond order section[edit]


I'm confused... I just studied from the Books of Pettifor and Suttun. And they seem to define bond order as something very different, thatn what is the article.

In those books, bond order is half the difference of the nuber of electrons in the bonding and those in the antibonding state. Example: A bond order of 1 means: Two electrons in the bonding and none in the antibonding state.

Wether the bond is sigma or pi doesn't have anything to do with bond order, but is determined by the angular momentum across the bond axis.

Could someone make the connection, please?

Mouvement 14:51, 9 April 2006 (UTC)Reply[reply]

This usually yields the same result. Think about it. --Spoon! 21:58, 29 August 2006 (UTC)Reply[reply]

Bond order as defined currently is usefully general; when defined as the difference between bonding and antibonding electrons it is specific to simple molecular orbital theory. And as written, the mention of sigma and pi bonds is correct, and fits with high school ideas.Ian 08:41, 30 July 2007 (UTC)Reply[reply]

Stronger than an ionic bond?[edit]

I've learned that ionic bonds are stronger than covalent bonds, since the ions have a greater amount of attraction between them. Can the person who stated that covalent bonds are stronger cite their sources? 05:30, 19 July 2006 (UTC)Reply[reply]

Sources are probaly their teachers instead of qualified scientists. The problem comes with the fact that there is no real line bewtween covalent and ionic bonding (there is a formal defination but thats just to make it easier to communicate). Also, how do you define bond strength and what two substances would you compare?

Polarity in ozone[edit]

Hi! I think ozone is a bad, or better, a too difficult, example, polarity in that molecule is for a different reason than electrons not being 'shared equally'. Ozone has two resonance structures. But either do not exist, the electrons are equally shared between the bonds (Lewis structures are only a model). The polarity in this molecule is more the result of the molecule not being linear, but bent. --Dirk Beetstra T C 22:44, 29 August 2006 (UTC)Reply[reply]

Okay, I was the one who put that there. I will retract it and talk about the polarity of ozone in chemical polarity. --Spoon! 08:32, 31 August 2006 (UTC)Reply[reply]
Maybe the C–C bond 1,1,1-trifluoroethane is a cleaner example? Due to the high electronegativty of F, C1 would be quite δ+, whereas C2 would not be. But by adding partial charges, one could argue that the effective electronegativity of the carbon atoms has changed. Semi-equivalently, one could consider that the bond is really between "the carbon on a methyl group" and "the carbon on a trifluoromethyl group", not just between two carbons, so the electronegativity difference of the group is what matters, not just the specific bonded atoms. DMacks 12:52, 31 August 2006 (UTC)Reply[reply]

unhelpful definition[edit]

as a student that is studying chemistry, I dont think the definition of the covalent bond is defined clearly.Missy1234 23:47, 17 January 2007 (UTC)Reply[reply]


Not to mention, it could be further defined into polar covalent and apolar covalent bonds, which although are redirected to this article, are in fact not discussed.

I would personally like to add a section on Lewis structures (aka. electron dot diagrams), polar and apolar covalent bonds, and co-ordinate covalent bonds.

However, most of my resources belong to the University of Technology, Sydney, Australia. Thus, the resources are unavailable to the public.

First sentence in particular[edit]

I'd like to second that the definition is unhelpful. I would fix it myself, but I came here to learn the definition!

The first sentence of the article currently reads "A covalent bond is a form of chemical bonding that is characterized by the sharing of pairs of electrons between atoms, and other covalent bonds." So "a covalent bond" is defined (partly) in terms of "other covalent bonds"? That seems circular... or have I not parsed the sentence correctly? — Preceding unsigned comment added by (talk) 18:15, 15 June 2011 (UTC)Reply[reply]

Unsaturated bond[edit]

The page for unsaturated bond redirects here.. but this page does not say anything about unsaturated bond. Maybe to chemistry students, this might be obvious, but as a public encyclopedia it should be clear exactly how this page relates to an unsaturated bond. as it is this page gives me no information and I am left completely in the dark as to what a unsaturated bond is. Drag-5 (talk) 18:41, 19 November 2007 (UTC)Reply[reply]

That does seem not-very-useful. I just re-redirected Unsaturated bond to Unsaturated compound. DMacks (talk) 19:05, 19 November 2007 (UTC)Reply[reply]

Article Needs Help, Bad First Picture[edit]

Sorry, but this article strikes me as rather poorly written, and, sorry again, I am not the guy to make the corrections. I hope someone more qualified agrees and takes the necessary steps. But that first picture!!--what a useless piece that is! Does ANYONE know what it means? If so, please give it a better description, or fix it. I am not clueless about chemistry, but I felt like I was, looking at that picture! What do those dashed lines and non-dashed lines mean? And what is the significance of the angles? And, okay, so those arrows are electrons, but...what do they mean??? You got three going one way and one going the other way... --Taquito1 (talk) 02:37, 10 February 2008 (UTC)Reply[reply]

That's actually a simplified molecular orbital diagram, and I must say it's actually quite well drawn. --Rifleman 82 (talk)
Actually, the energy gap for the right image should be smaller, since there is poorer size and symmetry overlap between both participating atomic orbitals (as defined by polar covalent). All things being equal, of course. --Rifleman 82 (talk) 03:23, 10 February 2008 (UTC)Reply[reply]

Text and Pic don't match[edit]

In the para before you present the Lewis diagram, the text says:-

"Some examples of Electron Dot Notation are shown in the following figure. An alternative form, in which bond-forming electron pairs are represented as solid lines, is shown alongside."

Well I've two problems with that:

1. There's only one figure so it should say "An example" not "Some examples"

2. The 2nd sentence says "An alternative form... shown alongside" - But it ISN'T!

I do wish someone who understands organic chemistry would clean this up, because I'd like to understand the solid line figures better. Edetic (talk) 10:06, 27 April 2008 (UTC)Reply[reply]

Noble gas covalent bonds? ???[edit]

How is it possible for noble gases to bond if their electron shell is full? I know noble gases can form compounds in special conditions, but it has to be impossible! Please answer!

Not my field, but there is some data on Noble gas compound which might help Ronhjones (talk) 00:45, 20 February 2009 (UTC)Reply[reply]

The last three noble gases can be "forced" into compounds. I will list these and their electronegativities(just to show what they would be bonding with covalently), however, please note that these compounds do not happen in nature, so are pretty much irrelevent to this article, also, these electronegativities are not very accurate, these are rough estimates...

Krypton: 3.0

Xenon: 2.6

Radon: 2.4

I do not know any examples of these compounds, if anyone would be so kind...

Many major chemical supply houses sell several noble-gas compounds: anyone with a moderate lab could make some and they have known synthetic longer really that unique or totally exotic. Please don't confuse "found in nature" with...well with anything that has much meaning about the importance of a chemical. DMacks (talk) 02:36, 8 March 2009 (UTC)Reply[reply]

double bond & triple bond[edit]

double bond & triple bond both direct here but this page hardly contains info on these topics. Should they redirect to pi-bond instead? V8rik (talk) 21:17, 6 April 2009 (UTC)Reply[reply]

i don't understand covalent bonding. Help please. —Preceding unsigned comment added by (talk) 22:54, 16 February 2010 (UTC)Reply[reply]

Animated picture[edit]

please insert a animated picture of sharing electron and differentiate it from transferring electron — Preceding unsigned comment added by (talk) 10:06, 3 May 2014 (UTC)Reply[reply]

Directional Properties should be included[edit]

I think that there is some useful material in the new section Directional Property of the Covalent Bond, added today by editor and deleted a few minutes later by Material Scientist. It is true that the editor is inexperienced and that this edit required revisions to both formatting and English to be acceptable, so I would not favor just putting it back in as is. But the edit does make the important point that we have little mention of orbital overlap and no mention of the difference between s-s, s-p and p-p direct and lateral overlap, i.e. sigma and pi bonds (though the edit didn't use those terms). So I think we need to insert a revised version of this edit to insert the important points, with the flaws fixed and possibly better integrated into the article. I will try to get to this soon if no one else does first. Dirac66 (talk) 17:08, 2 August 2015 (UTC)Reply[reply]

Covalent structures (macromolecular structure)problems[edit]

My school taught us that macro-molecular structure have a limited no. of atoms.For example protein, starch etc. graphite, diamond and quartz should be giant covalent structure which has no end. Am I right? if it's correct I'll change it. PS my chinese username won't show sorreh 13:24, 21 September 2015 (UTC) — Preceding unsigned comment added by 榎本徑 (talkcontribs)

First, I have moved this new section to the bottom of the talk page. From your examples, I think you meant to say that macro-molecular structures CAN have an UNlimited number of atoms, which is correct. Proteins have a large but definite number of atoms - for example all hemoglobin molecules have the same structure. Your other examples - starch, graphite, diamond, quartz - do in fact have an unlimited number of atoms, so have no end as you say. Dirac66 (talk) 14:11, 21 September 2015 (UTC)Reply[reply]
No. that's not what I meant. What I meant is that the example in the article may be wrong. Quartz, diamond, graphite are giant covalent NOT macro-molecular. Starch, plastic, protein are macro-molecular. 榎本徑 (talk) 14:09, 25 September 2015 (UTC)Reply[reply]
giant covalent are distinguished by their structure. Giant covalent substance's atoms usually form bonds with more than 1 other atom(eg each silicon or diamond(carbon)atom joins to 4 other. each graphite atom joins 3 other. In SiO2, each Silicon atom joins 4 Oxygen atom,while each oxygen joins 2).Giant covalent is usually a 3D network and its mp and bp (>1000°C) are often much higher than macromolecular(~300-600°C). In macromolecular, the structure is basically more like a linear chain of atoms with branches instead of a 3D network. It is a big difference. Maybe consider not mixing them together?榎本徑 (talk) 14:08, 25 September 2015 (UTC)Reply[reply]
Yes, it is true that most (though not all) authors distinguish macromolecular and giant covalent. And I agree that this distinction will be useful to many readers so I will mention the difference in the Covalent structures section. Also I don't think there is any unanimity about three types (as the article now says) or four types (if giant covalent is added), so I will just say several types. Dirac66 (talk) 20:13, 26 September 2015 (UTC)Reply[reply]
Does the literature actually call these "giant covalent", or is that just a lay-language description for Network covalent bonding? DMacks (talk) 20:44, 26 September 2015 (UTC)Reply[reply]
I forgot about network covalent which does sound more scientific and more clearly excludes chain macromolecules. A fast Google search gives 17 900 hits for "giant covalent" and "10 900" for "network covalent". More technical papers I suspect would more often favor "network covalent" though I haven't checked. So I think it is best to mention both names, with network covalent first as it is clearer and also corresponds to the name of another article. Dirac66 (talk) 23:08, 26 September 2015 (UTC)Reply[reply]
The kind of material is "network solid" (a redirect), focusing on the overall structure and properties rather than the facts of the bonds within it. That's another >50K google hits. DMacks (talk) 02:44, 27 September 2015 (UTC)Reply[reply]

Requesting Hyperlink to Wikipedia article on Metallic bonding[edit]

In the second paragraph, where the types of covalent bond are listed, each type includes a hyperlink to the appropriate Wikipedia page except the words "Metal-to-Metal bonding". I cannot add the edit myself since this page is locked, would someone can please hyperlink the text "Metal-to-Metal bonding" at the beginning of the second paragraph to the article at:

Thank you!

Pharcsa (talk) 15:28, 26 February 2016 (UTC)Reply[reply]
Done. Dirac66 (talk) 16:20, 26 February 2016 (UTC)Reply[reply]

Quantum mechanical description move to Chemical bonding model article[edit]

As there seems to be an article that specializes in talking about Valence bond theory and Molecular orbital theory (Chemical bonding model), I have decided to move the section there with a brief introduction here.--Officer781 (talk) 02:24, 7 June 2016 (UTC)Reply[reply]

Update: Moved back and converted chemical bonding model to a disambiguation.--Officer781 (talk) 14:38, 19 February 2019 (UTC)Reply[reply]

No one calls covalent bonds “molecular bonds”, and no one should. Please remove this erroneous statement given in the first sentence of this article.[edit]

This article states that covalent bonds are “also called…molecular bonds”. This is not common terminology and I cannot find any reputable source which uses it. The IUPAC gold book (and every other colored IUPAC book) has no mention of it. Moreover, it is a gross misnomer, as a “molecular bond” implies a bond between molecules, i.e. it is an intermolecular-bond, such as hydrogen bonding or pi-pi interactions between neighboring molecules. Whereas covalent bonds are explicitly intramolecular-bonds, and are never (correctly) referred to as “molecular bonds”. If there is no citation for who calls these molecular bonds, this should be removed to avoid father confusion for new chemists, which is recurring due to this inaccuracy. — Preceding unsigned comment added by Gilbert N. Lewis (talkcontribs) 18:34, 6 August 2019 (UTC)Reply[reply]

Diborane: Electron deficient or not? (conflicting information)[edit]

This page uses diborane as an example of an electron deficient compound, while the main Wikipedia page on electron deficiency explicitly states it is not. I do not have enough knowledge of the matter to decide which is true, but this conflicting information should be corrected by someone who does. — Preceding unsigned comment added by PurplePandoran (talkcontribs) 15:53, 31 January 2021 (UTC)Reply[reply]

Diborane has always been described as an electron deficient compound because there are 4 "bonds" in the central ring and only 4 electrons. more recently it has been seen as perfectly normal, but the "electron deficient" tag remains. It depends how you define "electron deficient". --Bduke (talk) 22:48, 31 January 2021 (UTC)Reply[reply]

Topic to be clear and proper[edit]

Can u clearly write in the details what exactly you are trying to explain . (talk) 12:59, 27 December 2021 (UTC)Reply[reply]

Can you please clarify exactly what you are asking? --Bduke (talk) 21:07, 27 December 2021 (UTC)Reply[reply]

What is mean by covalent bonding[edit]

Voice (talk) 02:06, 12 November 2022 (UTC)Reply[reply]