Talk:Sigma bond

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I removed this picture due to several objections:

1- it's kind of crude. 2- the animation flips by waaay too fast. 3- The text moving around made me feel a little sick 4- The "hydrogen atoms feel an attraction" is not a particularly useful description of what's going on, this hardly does justice to the notion of orbital overlap and wavefunction sums, and isn't particularly distinctive with respect to say, ionic bonding. 5- If we were to reject grounds #4, the phenomena isn't particular to sigma bonds, except for the fact that we are seeing two "hydrogens" coming together, Pi and Delta bonds work the same way.

Sigma bonding in Hydrogen molecules

"sigma bond rule"[edit]

"According to the sigma bond rule, the number of sigma bonds in a molecule is equivalent to the number of atoms plus the number of rings minus one."

Wait, but from a graph theory perspective, isn't this basically saying the number of sigma bonds equals to the number of "edges"? Ahyangyi (talk) 04:17, 7 December 2016 (UTC)

Yes, I think the sigma bond rule is probably equivalent to some graph theory result expressing the number of edges (bonds) in a graph (molecule) as a function of the number of vertices (= atoms) and the number of rings. If someone can find a source we could insert this equivalence into the article.
That does not imply, however, that whoever formulated the "sigma bond rule" in chemistry was necessarily aware of the graph theory result. It would also be interesting to know the history of the rule in chemistry, again with a source. Dirac66 (talk) 18:44, 8 December 2016 (UTC)