Are all bond-forming processes exothermic?

Question

If so, why don't helium form bonds with neon?

Related: Is Bond Formation “Strictly” Exothermic? – Sep 04 '16 at 09:49 — , Sep 04 '16 at 09:49
Downvoter: how could I make this question better? – DHMO Sep 04 '16 at 12:01 — DHMO, Sep 04 '16 at 12:01

score 1 · Accepted Answer · answered Sep 04 '16 at 10:39

1

Yes they are, but

(1) a reaction only occurs spontaneously if it is exergonic at the given temperature, and

(2) it might not be the kind of bond you wanted. He and Ne like it much better with a van-der-Waals bond between them, and

(3) creating the spiecies that can bond can take a large amount of energy. Vaporising a solid, splitting diatomic gases, forming some unheard of He+Ne radicals, etc., and

(4) if the bond is endothermic, it simply won't form, because it is not a bound state.

Point 2-4 are basically redundand, just different ways to look at it.

answered Sep 04 '16 at 10:39

Karl

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why don't helium form bonds with neon? – DHMO Sep 04 '16 at 10:47
Because any bond you could imagine, except a vdW-Bond, would be endothermic, i.e. not a bond. https://en.wikipedia.org/wiki/Noble_gas – Karl Sep 04 '16 at 11:49
So there are indeed endothermic bonds. – DHMO Sep 04 '16 at 11:54
1

Those are not bonds, because they do not bind at all! – Karl Sep 04 '16 at 11:59
So you're saying that if I used magic to form this molecule: $\ce{He-N}$ then the single bond would not be a bond? – DHMO Sep 04 '16 at 11:59
There is no such thing as magic. EoD. – Karl Sep 04 '16 at 12:09
I meant, if this molecule existed, the single bond would not be a bond? – DHMO Sep 04 '16 at 12:10
"the single bond would not be a bond?" doesn't make any sense. Once you move away from covalent bonding, there is almost never such a thing as a single bond, double bond, triple bond, etc. – pentavalentcarbon Sep 05 '16 at 17:07

score -5 · Answer 2 · answered Sep 04 '16 at 09:23

i think that helium and neon are both noble gases and hence do not form bonds(because bonds are meant for those atoms who have more electrons or less electrons).yes bond forming is exothermic(courtesy https://answers.yahoo.com/question/index?qid=20090822024552AAB8qjv).

Are all bond-forming processes exothermic?

2 Answers2