Discuss briefly the following:
(a) Greenhouse gases
(b) Catalytic converter
(c) Ultraviolet B
Answers
b) used to soke smoke of car.
Answer:
(a) Greenhouse gases
This effect refers to the global increase in the average temperature of the Earth as a result of greenhouse gases. These gases are methane, carbon dioxide and water vapor. When solar rays are incident on Earth, some of these are absorbed which are released back into the atmosphere. The greenhouse gases present in the atmosphere trap these radiations which helps in keeping Earth warm, hence suitable for humans to survive. Therefore, increase in the level of greenhouse gases can lead to an increase in the temperature of Earth overall resulting in Global warming.
(b) Catalytic converter
These are devices fixed in automobiles to lessen the vehicular pollution and contain expensive metals such as palladium, platinum and rhodium that serve as catalysts. When the vehicular discharge passes through the catalytic converter, the unburnt hydrocarbons found in it is converted into water and carbon dioxide. Nitric oxide and carbon monoxide liberated by catalytic converters are converted into nitrogen gas and carbon dioxide respectively.
(c) Ultraviolet-B
It is an electromagnetic radiation possessing a short wavelength compared to the visible light. They are produced by Sun, and are harmful rays which penetrate through the ozone hole on the surface of the Earth. UV-B poses many health hazards in humans, it damages DNA, activating the skin ageing process. These rays are also known to cause skin cancer and skin darkening. High levels of UV-B causes corneal cataract in humans.