Question

a student proposes the following lewis structure for the nitrite (no₂⁻) ion.
\

$$\begin{bmatrix}:\\ddot{o}-n = \\ddot{o}:\\end{bmatrix}$$

⁻
assign a formal charge to each atom in the students lewis structure.

atom	formal charge
n
right o

Explanation:

Step1: Recall formal - charge formula

The formula for formal charge is $FC = V - N - \frac{B}{2}$, where $V$ is the number of valence electrons, $N$ is the number of non - bonding electrons, and $B$ is the number of bonding electrons.

Step2: Calculate formal charge of left O

Oxygen has 6 valence electrons ($V = 6$). In the given Lewis structure, the left O has 6 non - bonding electrons ($N = 6$) and 2 bonding electrons ($B = 2$).
$FC_{left - O}=6 - 6-\frac{2}{2}=6 - 6 - 1=- 1$

Step3: Calculate formal charge of N

Nitrogen has 5 valence electrons ($V = 5$). It has 0 non - bonding electrons ($N = 0$) and 8 bonding electrons ($B = 8$).
$FC_N=5 - 0-\frac{8}{2}=5 - 4 = 0$

Step4: Calculate formal charge of right O

Oxygen has 6 valence electrons ($V = 6$). The right O has 4 non - bonding electrons ($N = 4$) and 4 bonding electrons ($B = 4$).
$FC_{right - O}=6 - 4-\frac{4}{2}=6 - 4 - 2 = 0$

Answer:

atom	formal charge
N	0
right O	0