When solar radiation strikes an oxygen molecule (O₂), it can cause the molecule to dissociate into two oxygen atoms (O). This process is called photodissociation.

Here's the chemical equation:

O₂ + UV light → 2O

The UV light provides the energy needed to break the bond between the two oxygen atoms.

Note: The oxygen atoms produced are very reactive and can then participate in other chemical reactions, such as the formation of ozone (O₃).