Q1: Which one of the following gases is most significant as air pollutant

ANS:D - Sulphurdioxide.

Among the options provided, Sulphur dioxide (Sulphurdioxide) is the most significant as an air pollutant. Sulphur dioxide (SO2) is a toxic gas produced primarily by burning fossil fuels containing sulfur compounds, such as coal and oil. It is a major contributor to air pollution, particularly in urban and industrial areas where combustion processes are prevalent. Exposure to sulphur dioxide can lead to various health issues, including respiratory problems, aggravation of asthma, and cardiovascular effects. Additionally, sulphur dioxide contributes to the formation of acid rain when it reacts with water vapor and other atmospheric components, leading to environmental degradation and damage to ecosystems. While carbon dioxide (CO2) is also a significant greenhouse gas contributing to climate change, sulphur dioxide is considered a more potent air pollutant due to its immediate health impacts and environmental consequences. Oxygen and nitrogen, on the other hand, are essential components of the atmosphere and are not typically considered air pollutants at normal concentrations.