Hi there
my question is short , and may be simple , but it really made me confused
now ,, Nitrogen has valence = 3 ,, Oxygen has valence = 2
definition of valence = max. number of bonds the atom can make
then , Nitrogen must have 3 bonds as a maximum , and a pair of unshared electrons
also , Oxygen must have 2 bonds as a maximum , and 2 pairs of unshared electrons
but the problem is that I see many compunds that have Oxygen with 3 bonds or sometimes 4 !!!
also Nitrogen with 4 bonds !!!
how it could be just like that ?