The reaction of $.....$ with $O_3$ leads to a decrease in the concentration of ozone by approximately $40\%$.

Name the acids present in acid rain and state their sources in rainwater.

Which is not a renewable source?

The conversion of sulfur dioxide to sulfur trioxide in the absence of a catalyst is a slow process. However,this process occurs easily in the atmosphere. Describe how this happens and write the chemical equations for the formation of $SO_3$ from $SO_2$.

Define environmental chemistry.

The insecticide $DDT$ is considered as . . . . . .