How do we utilize Lewis structure in simple species such as nitrate ion?

1 Answer
Apr 4, 2017

Answer:

Lewis structure is simply electron counting..........

Explanation:

Let's take the nitrate, anion, #NO_3^(-)#. Nitrogen comes from Group 15, and has five valence electrons, oxygen comes from Group 16, and has six valence electrons.

And thus we have to distribute #5+3xx6+1=24# #"electrons"# around the nitrate core...........Why did I add an extra electron?

And thus, #O=N^(+)(-O^(-))_2#, distributes #6#, #4#, and #2xx7# valence electrons around #O=#, #N#, and #O^-# respectively, and this (with the 2 inner core electrons) accounts for the charge on the atom, neutral, positive, or negative: i.e. #N, Z=7;O, Z=8#.

As always, the charge on the atom is the difference between the nuclear charge, and the electronic charge. For more of the same see here.

What about #NH_3#, and #NH_4^+#?