Lewis structures: Exercise 3

The formal charge of an atom is the difference between the number of outer electrons and the sum of the number of lone electrons and the number of bonds

P: 4 bonds → 4 e^- Neutral atom→ 5 e^- Charge: 5-4=1

P: 4 bonds → 4 e^- Neutral atom→ 5 e^- Charge: 5-4=1 O: 1 bond → 1 e^- 3 lone pairs → 6 e^- Neutral atom→ 6 e^- Charge: 6-(1+6)=-1 Cl: 1 bond → 1 e^- 3 lone pairs → 6 e^- Neutral atom→ 7 e^- Charge: 7-(1+6)=0

N: 3 bonds → 3 e^- Neutral atom→ 5 e^- Charge: 5-3=2 O (left): 1 bond → 1 e^- 3 lone pairs → 6 e^- Neutral atom→ 6 e^- Charge: 6-(1+6)=-1 O (right): 2 bonds → 2 e^- 2 lone pairs → 4 e^- Neutral atom→ 6 e^- Charge: 6-(2+4)=0

Formal charges in Lewis structures

Exercise 3