Question

How is ozone made in the atmosphere?

Answer 1

Ultraviolet radiation from the sun interacting with oxygen molecules.

Explanation:

Molecular oxygen contains 2 atoms. When they are struck by ultraviolet light from the sun they will split into individual atoms. When one of those individual atoms joins with a oxygen molecule (2 oxygen atoms) you get ozone, or `O_3` . That ozone molecule can now absorb ultraviolet light and disassociate again.

There is a little more going on but I think this should answer your question.