Nitrogen dioxide is a covalent compound. How many oxygen atoms are in a nitrogen dioxide molecule?

1 Answer
Nov 28, 2016

In #NO_2#? Well I think you can count them yourself.

Explanation:

#NO_2# is an interesting molecule; because it is a radical species with a formal, lone electron on the central nitrogen:

i.e. #O=N^(+)-O^(-)#

On the central nitrogen, there are FOUR valence electrons, i.e. there is a nitrogen-centred single electron. That there are 4 valence electrons rather than 5 justifies our distribution of a formal positive charge to this site. Because of this single electron, we can rationalize the formation of #N_2O_4#, where the single electrons couple to form a #N-N# bond:

#2NO_2 rarr N_2O_4#

A Lewis structure of #""^(-)O(O=)N^(+)-""^(+)N(=O)O^-# is usually invoked.