Ozone is formed when

a. two oxygen molecules combine
b. an individual oxygen atom combines with an oxygen molecule
c. ultraviolet radiation breaks apart four oxygen molecules
d. oxygen molecules are broken into separate atoms

Explanation:

The highly reactive form of oxygen is ozone. It is made up of three atoms of oxygen. Ozone layer protects us from harmful radiations that are coming from sun i.e. UV rays. It is formed due to the combination of nitrogen oxides and organic compounds.

The UV rays coming from sun strikes an oxygen molecule. It then spilts into two free oxygen atoms. At last, the free oxygen atom interacts with oxygen molecules and thus ozone forms.

Hence, the correct option is (A) '' two oxygen molecules combine ''.

dang that balls went far

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.