Draw the Lewis structures for three resonance forms of the nitrate ion, NO−3 . Include electron lone pairs, and any formal charges.

Answer 1

As mentioned earlier, can' easily draw on the Wyzant platform but will do my best and describe how to draw it.

NO₃^- (be careful when you write this as it is NOT NO-3 as you wrote it in the question)

N has 5 valence electrons

O has 6 valence electrons x 3 = 18 valence electrons

minus 1 means 1 extra valence electron.

TOTAL valence electrons to be used = 5 + 18 + 1 = 24 valence electrons.

Put N in the center surrounded by 3 O atoms. Put a double bond to one of the O atoms, and leave singe bonds to the other 2 O atoms. That is one resonance structure. Then move the double bond to another O atom leaving single bonds to the other 2. That's a 2nd resonance structure. Finally move the double bond to the last O atom. For all of these structures, you should put brackets around it [ ] and put a -1 sign outside the bracket. Also, you should put 3 lone pairs of electrons around each O atom that is singly bonded to N and 2 lone pairs around the double bonded O atom.

As for formal charges, the O atom that has a double bond has a formal charge of zero.

The other 2 O atoms that have single bonds each have a formal charge of -1

The N atoms in all cases has a formal charge of +1

The total of all formal charges adds up to -1 which is the charge on the ion.