Question

1. write the resonance forms of ozone, o₃, the component of the upper atmosphere that protects the earth from ultraviolet radiation. what is the order of the bonds in o₃?

Explanation:

Step1: Determine the resonance structures

Ozone has two resonance structures. In the first structure, one oxygen - oxygen bond is a double bond ($O = O$) and the other is a single bond ($O - O$). In the second structure, the positions of the double and single bonds are reversed.

$$\begin{array}{c} \overset{-}{O}-\overset{+}{O}=O\\ O=\overset{+}{O}-\overset{-}{O} \end{array}$$

Step2: Calculate the bond order

The formula for bond order is $BO=\frac{\text{Number of bonding electron pairs}}{\text{Number of bonds}}$. In ozone, there are 3 bonds (two $O - O$ bonds in total when considering resonance) and 3 bonding electron pairs (the equivalent of 1.5 bonds per $O - O$ interaction).
$$BO=\frac{3}{2}=1.5$$

Answer:

The resonance forms are $\overset{-}{O}-\overset{+}{O}=O$ and $O=\overset{+}{O}-\overset{-}{O}$, and the bond order of the $O - O$ bonds in $O_{3}$ is $1.5$.