The following reactions take place in the ozone layer by the absorption of ultraviolet light.

A. O3 → O2 + O•

B. O2 → O• + O•

Which of the reactions, A or B, requires a shorter wavelength of light?

Option B will require a shorter wave length of light.

Explanation:

The bonding between Ozone (O3) and Oxygen (O2) can be used to explain why the breaking of oxygen into Oxygen radicals will require a shorter wave length.

The bond between Oxygen (O2) is a double bond while Ozone (O3) has an intermediate bond between a double bond and a single bond. The bond order of Oxygen (O2) is equals 2 while that of Ozone (O3) is 1.5. Since the bond order of oxygen is higher, it will require more energy to break the bond compared to breaking the Ozone (O3) bond. Recall that Energy is inversely proportional to wave length. So it will require a shorter wave length to break the Oxygen (O2) into its radicals.