Air Pollution

• Classical smog, also known as London smog or Sulphurous smog, is formed when there is high concentration of sulphur dioxide and particulate matter produced due to combustion of fuels. It occurs in cold and humid climate and has reducing nature.
• Photochemical smog, also known as Los Angeles smog, is formed when sunlight acts on the oxides of nitrogen and hydrocarbons produced from factories or by automobiles. It occurs in warm and dry climate and has oxidising nature.

Acid rain is a mixture of wet and dry deposition (deposited material) from the atmosphere containing higher than normal amounts of nitric and sulfuric acids. Sulfur dioxide ($SO _2$) and nitrogen oxides (NOx) are the principal pollutants, that cause acid precipitation. $SO _2$ and NOx emissions released to the air react with water vapor and other chemicals to form acids that fall back to earth. The majority of NOx comes from cars, buses, trucks, and other forms of transportation and from power plants. Therefore, the correct answer is option E.

Waldsterben refers to the mass death of the trees wherein, the peripheral parts of the plants are killed and slowly the entire forest population dwindles. It was first reported in Germany in the early 1980s. The atmospheric pollution was the main cause of such deaths of trees. Tropospheric ozone is the secondary pollutant. Nitrogen oxides and sulphur oxides are released by the industrial emissions and vehicular exhausts. Acid rain is the chemical reaction between these oxides and water to form their respective acids that precipitate with the rains. The pollutants have severe effects on the trees.

Atmospheric aerosol particles can be defined as any solid or liquid droplets suspended in the atmosphere. Fog, Dust, smoke are examples of aerosol. Aerosols increase atmospheric albedo due to which the rate of photosynthesis by plants on earth is decreased. Albedo is the part of the energy from the sunlight reflected back into the atmosphere. 

Photochemical smog is composed mainly of ozone (O$ _3$), Peroxyacetyl nitrate (PAN) and NOx. It is often called brown air where solar radiation is intense. In areas or seasons of lesser solar radiation smog formation is incomplete and the air is referred to as grey air.

Aerosols are minute particles suspended in the atmosphere and are known to reduce primary productivity on earth. scattering and absorption of sunlight by anthropogenic aerosols reduce photosynthetically active radiation, (PAR) incident upon the Earth’s surface, but increase the fraction of the PAR that is diffuse.

Air pollution is defined as the presence of substances in the atmosphere at concentrations high enough to interfere with human health, safety, or welfare, or to produce other harmful environmental effects.

SPM (Suspended Particulate Matter) is defined as particles floating in the air with a diameter below 10um. Studies have shown that high SPM concentrations in the air can have a detrimental impact on respiratory organs. SPM is generated both from natural sources (e.g.,volcanoes or dust storms) and human activities (vehicles, incinerators and industrial plants)

Catalytic converter is a device designed to reduce the amount of emissions from automobiles.The current (so - called three - way) systems use a heated metal catalyst to reduce the emissions of carbon monoxide CO),hydrocarbons and nitric oxide (NO), all of which contribute to the formation of photochemical smog. In an automobile's exhaust system, a catalytic converter provides an environment for a chemical reaction where unburned hydrocarbons undergoes complete combustion. Hence the combustion process continues but outside the engine combustion chamber where no useful energy is extracted.Toxic car gases such as unburned hydrocarbon (UHC) and carbon monoxide(CO) would not exist if the fuel to energy conversion in the engine were perfect.

So, the correct answer is 'If both the assertion and reason are true but the reason is not a correct explanation of the assertion'

Air pollution is typically more severe in areas with high human activity, such as cities, industrial zones, and densely populated regions, due to increased emissions from transport and industry.

Acid rain and other pollutants react with building materials like limestone and metal, causing chemical degradation known as corrosion.

Plant sensitivity to air pollution is primarily influenced by the plant's physiological state and environmental factors, but among the choices, fertility is a key factor affecting growth and stress response. The other options are either unrelated or secondary to the fundamental biological sensitivity.

Aerosols are defined as a suspension of fine solid particles or liquid droplets in a gas. This is a standard scientific definition used in atmospheric science.

CFC is found to destruct the ozone layer. It is found to be contaminating air. Cooling electronic gadgets are the major source of CFC.

Coal plants are the nation’s top source of carbon dioxide emissions, the primary cause of global warming. Burning coal is also a leading cause of smog, ash, acid rain, and toxic air pollution.

The trapping of infrared radiations from the atmosphere and not reflecting it back due to higher levels of Carbon dioxide as a major pollutant which traps radiations. This effect causes the rise in the global temperature resulting in melting of polar ice caps and rises in the sea level.