General Awareness Questions

Secondary pollutants include ozone, which is formed when hydrocarbons (HC) and nitrogen oxides (NOx) combine in the presence of sunlight.

Whereas Primary pollutant are those pollutants that are directly emitted from their sources, like CO2, CO, SO2 as these gases are directly emitted form burning of fossil fuels.

Acid rain, which is formed when sulfur dioxide or nitrogen oxides react with water, sulfuric acid etc.

Hence, Acidrain is a secondary air pollutant.

There are lots of reasons behind the flood in any area but the main reason is a heavy downpour or rapid snowmelt can flood canyons with a mixture of soil, rock, and water is a major cause of floods.

When the spring times come, sometimes there's a lot of warmth that suddenly comes, especially nowadays when there are things such as global warming. So the snow melts and large amounts of water can flood the fields that are often found at the foot of a mountain or similar things.

But they may also be caused by deforestation, drainage channel modification from a landslide, earthquake or volcanic eruption. Examples include outburst floods and lahars.

Mark Fields

New York City, London, and Tokyo are the richest cities in the world 2018, according to their ranks.