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Dear author, in the Formation section,second line......Electron affinity of an atom should be negative for it to accept electrons and form an anion. It is the energy released. ([User:Mani_g1|Dr. Manisha Jain]) —Preceding unsigned comment added by Mani g1 ( talk • contribs) 13:41, 5 May 2011 (UTC)
I was taught that the difference in electronegativity between the atoms in an ionic bond is greater than 1.25, and anything less is Polar Covalent. The article mentions electronegativity but does not go into enough detail to explain what's going on. 76.123.165.106 ( talk) 22:25, 18 January 2009 (UTC)
How about a nice caption to say something about the figure - what it represents, how it was made, etc.? -- Marj Tiefert, Wednesday, May 14, 2002
I've done a faily major reformat of this page. If it looks bad to anyone please reformat, or alternativly say what the problem is on this page along with their browser and screen resolution. I'm a bit worried about the equation overlapping the table on the right, which I think it might do with a small enough screen size Theresa knott
Would be great if someone could add a paragraph discussing how exactly they're different from covalent bonds. Tempshill 20:46, 24 Sep 2004 (UTC)
Since the Lithium and Fluorine atoms are both electrically neutral prior to bonding, what causes an electron to "leave" the Lithium atom for the Fluorine atom in the first place? -- RussAbbott 02:27, 17 Nov 2004 (UTC)
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doesn't litium have three electrons? I don't think the diagram is right
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It is energetically unfavorable to transfer an electron from Lithium to Fluorine to form separate ions. However, quite a lot of energy is released when the ions pack into the lattice, and this more than compensates for the energy required to form the ions.
I am somewhat suspicious of the statement that no bond is purely ionic. In the compound sodium borohydride, there are Na+ and BH4- ions. There are no lone pairs available on BH4- to share with sodium, so how can there possibly be any covalency?
Well the bond starts off as a covalent bond, with the two atoms sharing lithium's single valence electron. However, their electrongativities are 1.0 for lithium and 4.0 for fluorine. The electronegativity of fluorine is obviously much stronger, so it pulls the electron closer to itself, until it gets to the point that the electron has comletely left lithium and has completed fluorine's octet. 24.188.27.7 03:35, 11 December 2005 (UTC)
Ionic Bonding
Ionic bonding reminds me of the mooring lines that get cast into the harbour when the big ship arrives. A sodium atom sails close to a chlorine atom. It takes an interest in it, and then it casts over a mooring electron. The two atoms then haul themselves together. Clearly the bonding has begun before the official explanation for the bond has even come into existence. See 'Gravity Reversal and Atomic Bonding' at http://www.wbabin.net/science/tombe6.pdf Yours sincerely, David Tombe ( 124.217.36.28 12:22, 8 December 2006 (UTC)).
Re: Li and F reaction. I think it is a mistaken notion that they should not react. The most stable state for lithium and fluorine are as lithium cations and fluoride anions. That is the most common state you would find them in nature, i.e., the same electronic configuration as their nearest noble gas. You must supply energy to convert a lithium cation to lithium metal. That energy suggests lithium is sufficiently reactive to enable it to react with water. I understand the reason to ascribe elements as 0 kJ/mol in their elemental states, but that wrongly implies they are actually at some neutral state. Petedskier ( talk) 23:03, 21 May 2012 (UTC)
'ion pair' redirects to this page, but there is no mention of it in the article. From what i understand it is a case when two ions which perhaps were formally attached are still next to each other, but not necessarily bonded. Does this sound about right? Do they influence each other significantly?
Hang on a a day!! Not a minute! This is wrong. The first paragraph states a nonpolar covalent bond is weaker than a covalent polar bond. Okay. But you CAN'T use that to determine if an ionic bond is stronger than a covalent. Because Covalent bonding is very very strong between the actual atoms involved and weak only as an intermolecular force. Ionic bonds are between molecules as in a lattice (intermolecular) and between the actual ions. To prove this, you only need to look at Diamond, Carbon-Carbon bonds, all covalent 100%, with no degree of ionic behavior. Diamond is the hardest material in the world. So I shall remove this very damaging bit at the first paragraph, unless someone with more real scientific knowledge (like a degree or something) rules me wrong. Tourskin.
Ionic bonds are generally stronger than covalent bonds. Any plausible arguments as to say otherwise? Correctist ( talk) 02:16, 31 January 2008 (UTC)
There are some problems here of accuracy.
Polarisation effects - this para is pretty good until it says AlCl3 is covalent! Its an ionic solid (6 coordinate Al) and forms 4 coordinate Al dimers (covalent) only in the melt and gas phase.
Ionic structure - What is this paragraph saying- is there a confusion here with metal structures where some metals approximate closest packing with hcp and fcc structures being common (bcc isn't closest packed)? Simple cubic what is that? In the unit cell the weight is one of the atoms? In an ionic solid the unit cell has to contain at least one formula unit i.e 2 different atoms. Keeping it really simple and only considering binary ionic compounds - there are two factors - the ratio of positive to negative and the relative sizes of the two ions involved.
Ionic v Covalent - the assertion that covalent bonding is determined by VSEPR overstates the power of VSEPR - which best predicts molecular shapes of main group compounds (inert pair effect and inner shell polarisation effects ignored).
--
Axiosaurus (
talk)
09:41, 13 August 2008 (UTC)
I changed the heading to "Common name" from the previous heading "Stock System Name" If there ever was a formal Stock system for ions, it has now, 80 years or so later, been superseded many times, most recently by IUPAC latest 2005 recommendations. -- Axiosaurus ( talk) 17:09, 14 April 2009 (UTC)
The author of the papers is the author of the section in the wikipedia article:
Some charge transfer (i. e., ionic character) can exist even in pure elemental crystals, if atoms occupy symmetrically inequivalent positions - but usually such ionic character is too small to be important. Significant charge transfer was recently reported in a high-pressure phase of boron, [1] which consists of two types of clusters: B12-icosahedra and B2-pairs, arranged as ions in a NaCl-type structure, with charge transfer of ~0.5 electrons from B2 to B12.
We have to decide If this is notable enough to keep.-- Stone ( talk) 20:18, 11 May 2009 (UTC)
I'm tempted to delete the entire section listing common ions, as (1) it is of limited usefulness, (2) it is incomplete, (3) it cannot be completed practically, (4) there is already Category:Cations and Category:Anions, and (5) there is already a list of representative ions at Ion. Any objections?— Tetracube ( talk) 16:32, 11 June 2009 (UTC)
In the page there is a segment dicussing that all ionic bonds must have some covalent nature. It also dicusses the percent of ionicity. It would be useful to also include the equation by which percent ionicity can be calculated. % ionic character of a bond = 1 - exp (1/4 * delta chi ^2) where delta chi is the difference between electronegativity of the anion and cation. Also in response to the below comment about electronegativity - linking to the page on electronegativity is a legitimate explanation for electronegativity. —Preceding unsigned comment added by 128.61.137.218 ( talk) 16:01, 10 December 2009 (UTC)
I agree with the above, but a reference would be necessary. Also, adding a diagram illustrating the ranges for the three types of electrochemical bonds (ionic, polar covalent, and non-polar covalent) would be useful. Mego ( talk) 04:56, 30 December 2009 (UTC)
Ach ja.. und , deine Mudda !!! —Preceding
unsigned comment added by
80.146.238.147 (
talk)
13:05, 14 January 2010 (UTC)
It shouldn't. Ionic interactions refers to the weak electrical attraction which occurs between atoms that are already covalently bonded, e.g. in globular proteins. There doesn't appear to be a page for this type of interaction. :S —Preceding unsigned comment added by 62.30.209.82 ( talk) 18:23, 15 March 2010 (UTC)
In the summary section, the example of Sodium and Chlorine seems rather incomplete and simple as the bonding of complex ions require new sets of rules (parentheses...) . In other words, eg) MgSO4 + AlCl3 => MgCl2 + Al(SO4)3 Such "more complex" examples, in my opinion, should be added. -- Jjeong12 ( talk) 17:43, 21 June 2010 (UTC)
The new gif is nifty, but I'm a little concerned that it shows um... perhaps the gas-phase reaction of sodium with fluorine, rather than simply the ionic bond. -- Rifleman 82 ( talk) 22:50, 17 June 2011 (UTC)
I have a problem with the Formation section, but I'm not brave enough to make a change in it. The sentences that seem incorrect are:
"The removal of electrons from the cation is endothermic, raising the system's overall energy." and "However, the action of the anion accepting the cation's valence electrons and the subsequent attraction of the ions to each other releases energy and thus lowers the overall energy of the system."
In both cases, they are not cations or anions until they lose or gain the electron. They are just elements that become either cations or anions.
Hopefully someone with experience here at Wikipedia will make the correction. — Preceding unsigned comment added by Puntific ( talk • contribs) 21:03, 13 December 2011 (UTC)
This is not the first discussion of bond strengths. In the discussion there are comments on ionic v covalent bonds. I ended up on this article still trying to understand the differences in bond energies. What or how are bond dissociation energies for covalent bonds different than the bond strength of NaCl? What is actually measured in determining bond dissociation energy vs bond strength? Petedskier ( talk) 23:19, 21 May 2012 (UTC)
Ionic bonding exists but there is not really such thing as AN ionic bond. IMHO the article should therefore be renamed "ionic bonding". The term ionic bond should be avoided completely.
The term is wrong and very misleading because of what it suggests in analogy with covalent bonding: directionality and localized behavior. (For metallic bonding the same argument holds.) In an ionic compound like NaCl there is no single bond between one Na and one Cl. Each ion has six neighbors at angles of 90 degrees. This is completely incomprehensible from a covalent VSEPR point of view. Not everything is an organic molecule! Jcwf ( talk) 16:19, 6 November 2013 (UTC)
Jcwf ( talk) 01:01, 9 November 2013 (UTC)
The comment(s) below were originally left at Talk:Ionic bonding/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.
Rated "high" as high school/SAT biology content. - tameeria 00:33, 11 March 2007 (UTC) |
Substituted at 01:12, 22 May 2016 (UTC)
The last sentence in the lead doesn't quite work for me. "Here, the opposite trend roughly holds: the weaker the cohesive forces, the greater the solubility." The trend is only 'opposite' because of the terms in which it's expressed in the sentence; if you were to word it differently, the trend between melting point and solubility would be the same, which I believe is intuitively a better way to express this.
I think of it like this: The higher the charges, the stronger the cohesive forces and the stronger the melting point, and the lesser the solubility - which is what you would expect, there are stronger forces binding the ions together so they are more resistant to dissolving. It's a minor point, but I think that introducing the concept of an 'opposite trend' is unnecessarily confusing, and would propose simply striking that part out of the sentence as follows:
The higher the charges the stronger the cohesive forces and the higher the melting point. They also tend to be soluble in water. Here, the weaker the cohesive forces, the greater the solubility.
Any thoughts/comments? Girth Summit ( talk) 00:51, 5 November 2016 (UTC)
In the opening paragraph it states, "In the simplest case, the cation is a metal atom and the anion is a nonmetal atom, but these ions can be of a more complex nature, e.g. molecular ions like NH4+ or SO2 −4. In simpler words, an ionic bond is the transfer of electrons from a metal to a non-metal in order to obtain a full valence shell for both atoms."
These two sentences are inconsistent with each other (IE it states you can have NH4+ as a cation, yet then makes the common mistake of declaring all ionic compounds must have a metal and nonmetal). Ammonium salts are all ionic compounds that do not have a metal cation, yet they are ionic. I would change it myself but the article is semiprotected.— Preceding unsigned comment added by 167.88.240.8 ( talk) 18:35, 25 March 2019 (UTC)
Guys does ionic bonding happen purely because of a cation and anion bonding? Or it also happens because of two sharply contrasting electronegativities (as said by iupac [1]). Pls enlighten me! Ice bear johny ( talk) 07:02, 4 September 2020 (UTC)
References
There would seem to be something missing from this statement' Many sulfides, e.g., do form non-stoichiometric compounds. Ériugena ( talk) 15:37, 21 June 2021 (UTC)