Question

State True or False.

Stratospheric ozone is formed naturally by chemical reactions involving solar ultraviolet radiation (sunlight) and oxygen molecules.

• A. true
• B. false

Answer 1

The given statement is True.
Stratospheric ozone is formed naturally by chemical reactions involving solar ultraviolet radiation (sunlight) and oxygen molecules, which make up 21% of the atmosphere. In the first step, solar ultraviolet radiation breaks apart one oxygen molecule $\left(O_2\right)$ to produce two oxygen atoms $\left(2O\right)$. In the next step, oxygen atoms combine with undissociated oxygen molecules to form ozone molecules.
$O_2\stackrel{UV}{\to }2\left(O\right)$
$O_2+\left(O\right)\to O_3$.