# Why is a CO single bond stronger than a NO single bond?

Why is a CO sigma bond stronger than a NO sigma bond? I would think that since nitrogen and oxygen are of similar size and have similar atomic orbitals (because they are adjacent in the period), their MO "overlap" would be superior. Does it have something to do with their similar electronegativities "fighting" over the electrons?

• No, it doesn't. It is just the extra electrons. Think of F... or better yet, think of Ne; it has the same size and same orbitals, so why is there no $\ce{Ne2}$? – Ivan Neretin Apr 27 '17 at 6:52
• @IvanNeretin Octet rule. I'm not sure what point you are making here. C-O sigma bond has a greater bond energy than a N-O single bond. What "extra electrons" are you referring to? – Nova Apr 27 '17 at 10:10
• How many valence electrons are there in a CO molecule? How many are in NO? – Ivan Neretin Apr 27 '17 at 10:11
• What "single bond"? You mean sigma bonds in CO and NO molecules? – Mithoron Apr 27 '17 at 23:13
• @Mithoron exactly – Nova Apr 28 '17 at 4:09