Air Pollution Quiz

Air pollution is the contamination of air due to the presence of harmful substances in the atmosphere.

Some examples of air pollutants include gases like carbon monoxide and sulfur dioxide, particulates, and biological molecules.

Air pollution can damage the natural environment, such as causing climate change, ozone depletion, or habitat degradation.

Air pollution can be caused by both human activities and natural phenomena.

Air pollution can cause diseases, allergies, and even death to humans.

A semiconductor is a material that has an electrical conductivity value between that of a conductor and an insulator. Unlike conductors, its resistivity decreases as temperature increases, and unlike insulators, it can conduct electricity. The conducting properties of a semiconductor can be modified by introducing impurities into its crystal structure.

Impurities, also known as doping, are introduced into a semiconductor to alter its conducting properties. By selectively adding impurities, regions of different conductivity can be created within the crystal structure, forming a semiconductor junction.

The charge carriers in semiconductors include electrons, ions, and electron holes. These carriers play a crucial role in the behavior of semiconductors at junctions and are essential for the functioning of diodes, transistors, and other electronic devices.

Examples of semiconductors include silicon, germanium, gallium arsenide, and elements near the 'metalloid staircase' on the periodic table.

Gallium arsenide is the second-most common semiconductor after silicon. It is used in various applications such as laser diodes, solar cells, microwave-frequency integrated circuits, and more.