Question

photochemical smog forms when ____ and ____ are trapped by a thermal inversion and ozone, nitrogen dioxide and pan form.
select one:
○ a. carbon monoxide; sulfur dioxide
○ b. hydrocarbons; lead
○ c. carbon dioxide; lead
○ d. volatile organic compounds; oxides of nitrogen

Explanation:

Photochemical smog is formed through a complex series of chemical reactions involving volatile organic compounds (VOCs) and oxides of nitrogen ($NO_x$) in the presence of sunlight. When these pollutants are trapped by a thermal - inversion layer, ozone ($O_3$), nitrogen dioxide ($NO_2$) and peroxyacetyl nitrate (PAN) are formed.

Answer:

D. volatile organic compounds; oxides of nitrogen