Pollution (Old NCERT) - Free MCQ Practice Test with solutions, NEET NCERT

The greenhouse effect is a natural process that warms the Earth's surface. When the Sun's energy reaches the Earth's atmosphere, some of it is reflected back to space and the rest is absorbed and re-radiated by greenhouse gases. The absorbed energy warms the atmosphere and the surface of the Earth.

Lead does affect the kidney and CNS but its first target is RBC and through that onlt it travels inside the body to CNS and kidneys.

The presence of particulate matter in polluted air catalyses the oxidation of sulphur dioxide to sulphur trioxide. Oxides of Nitrogen: Di-nitrogen and di-oxygen are the main constituents of air. These gases do not react with each other at a normal temperature.

The main chemicals in air pollution that create acid rain are sulfur dioxide (SO2) and nitrogen (NO2). Acid rain usually forms high in the clouds where sulfur dioxide and nitrogen oxides react with water, oxygen, and oxidants. this mixture forms a mild solution of sulfuric acid and nitric acid.

The atmosphere surrounding the Earth is made up of many gases, the most prevalent of which are nitrogen and oxygen. It also contains water vapor, dust and ozone. In the lowest layer of the atmosphere the troposphere the higher up you go, the lower the temperature.

Air pollution like sulfur dioxide and nitrogen oxides can cause respiratory diseases, or can make these diseases worse. Respiratory diseases like asthma or chronic bronchitis make it hard for people to breathe. The pollution that causes acid rain can also create tiny particles.

Photochemical smog occurs in warm, dry and sunny climate. It is formed by the action of sunlight on unsaturated hydrocarbons and nitrogen oxides. Chemically, it is an oxidising mixture. It does not involve any smoke or fog.

Historic major sources of lead air emissions were motor vehicles and industrial sources. Motor-vehicle emissions have been reduced by the phasing out of leaded gasoline, but lead is still used in general-aviation gasoline for piston-engine aircraft. 

Troposphere is the lower layer of atmosphere. Its thickness is about the range of 0-12 km. In this layer, all types of pollutants are present i.e. gaseous pollutants and particulate pollutants. Gaseous pollutants consists SO₂, NO₂, CO₂, etc. Particulate pollutants consists smog, dust, fumes.

Global Warming Causes Stratospheric Cooling. The main reason for the recent stratospheric cooling is due to the destruction of ozone by human-emitted CFC gases. Ozone absorbs solar UV radiation, which heats the surrounding air in the stratosphere.