# Lone pairs of electrons and covalent bonding [closed]

Every time I saw a covalent bond structure, I notice that there are always lone pairs or no electrons left in the outer shell of the atoms. Is it compulsory for covalent bonds to have lone pairs or no electron in outer shell left to form ? Thank you.

• Well, check out NO!
– Ed V
Apr 21 at 16:21
• There are odd-electron species. Apr 21 at 16:27
• @NisargBhavsar So, you won’t take NO for an answer? ;-)
– Ed V
Apr 21 at 16:29
• @EdV I cordially invite you to Chemistry Chat, there's them puns. Sometimes. Apr 22 at 22:42
• And $\ce{H-H}$? Apr 23 at 20:49

Some common examples include nitrogen compounds due to its odd number of electrons in its ground state, such as $$\ce{NO}$$ with a bond order of 2.5.
Radicalization of an azo compound (formation of an especially strong $$\ce{N2}$$ triple bond):