Solution:
Concept- Photochemical smog, also known as summer smog, is caused by the chemical reaction of sunlight, nitrogen oxides, and volatile organic compounds in the atmosphere, which results in hazardous airborne particles and ground-level ozone. Primary pollutants, as well as the creation of secondary pollutants, play a role in a photochemical haze.The presence of both primary and secondary contaminants in the atmosphere affects photochemical smog. Nitrogen oxides, primarily nitric oxide and nitrogen dioxide, as well as other volatile organic chemicals that evaporate over a narrow temperature range, are the main pollutants. Peroxyacyl nitrates (PAN), tropospheric ozone, and aldehydes are examples of secondary pollutants found in photochemical smog.
Ozone, which is created when hydrocarbons and nitrogen oxides react in the presence of sunlight, is an essential secondary pollutant for photochemical smog. Nitrogen dioxide, which is generated as nitric oxide, reacts with oxygen in the air to form nitric oxide. Furthermore, when and are emitted, they are oxidised in the troposphere to nitric acid and sulfuric acid, which are the major components of acid rain when mixed with water. All of these harsh compounds are oxidising and highly reactive.
Hence, option 4 is correct.
