Ozone (O3) molecule is made up of three oxygen atoms. It is formed in the stratosphere when single oxygen atom combines with a molecule of oxygen i.e. when [O] combines with O2. Oxygen molecule consisting of two oxygen atoms splits into atomic oxygen in the presence of ultraviolet radiation. The atomic oxygen then combines with another molecule of oxygen to form ozone.
The reactions are as follows:
UV light
O2 ---------------> [O] + [O]
[O] + O2 ---------->O3
Hence, the statement given in the question is correct.
So, the correct answer is 'True'.