air and water pollution

Q1) What are CFCs?

Ans: ChloroFluoroCarbon

Q2) What is global warming ?

Ans: more heat is being retained in the earth's atmosphere, thus raising the earth's average temperature.

The gradual rise in the earth's average temperature is called global warming.

Q3) Write two diseases caused by drinking contaminated water.

Ans: typhoid and malaria

Q4) write two chemicals used to purify water

Ans: chlorine and Iodine

Q5) Name two greenhouse gases

Ans: Carbon monoxide and carbon dioxide

  

Q6) why does burning of fuels cause air pollution.

Ans: fuels burn, they produce gases such as Carbon dioxide, carbon monoxide, Sulphur oxide and nitrogen oxide. They are the air major pollutant of air.

Q7) How does the ozone layer protect life on earth?

Ans:  The sun emits ultra-violet rays, which are harmful to all kind of life forms from microorganisms to human beings. The ozone layer absorbs most of the ultra-violet rays and prevent them from reaching the earth's surface. This protect life on earth.

Q8) how are acid rains formed?

Ans: burning of fossil fuels adds Sulphur dioxide and nitrogen oxide into the atmosphere. Sulphur dioxide and nitrogen oxide reacts with water vapor and produce sulphuric acid and nitric acid. These acid mixes with rainwater making it highly acidic and falls as acid rain.

  

Q9) list two measures to prevent water pollution?

Ans: - bathing and washing cloths near water bodies should be discouraged

- biodegradable pesticides and fertilizers should be used

Q10) what is loading?

Ans: a process in which a chemical like alum that binds itself to the fine suspended particles is added into the water. It settles the particles at the bottom.

Q11) what is smog? How is it harmful

Ans: smoke combines with water vapour and suspended dust particles in the air, and in the presence of sunlight react to form photochemical smog. Smog forms a thick fog-like layer in the atmosphere and prevents the sunlight from reaching the earth.

This affects the normal functioning of plants. Smog is also known as asthma and cough.

Q12) explain the greenhouse effect and its consequences?

Ans: the earth receives heat from the sun. when the surface of the earth heats up, it radiates some of the heat towards space. The layer of greenhouse gases that surrounds the earth does not allow all the heat to leave the earth's atmosphere. It traps some of this heat, which keeps the ideally warm. This is known as greenhouse effect.

  

Q13) list the measures that you can prevent the earth from becoming warmer.

Ans: to prevent global warming, we must reduce the use of fossil fuels which add carbon dioxide in the atmosphere. Fossil fuels are used to run motor vehicles and thermal power plants to produce electricity.

Q14) what are the effects of drinking water contaminated chemicals?

Ans: Dumping untreated organic waste into oceans pollute the water .polluted ocean's water can cause rashes, earaches, eyes and respiratory infections, hepatitis encephalitis.

Chemically contaminated water can affect and damage the nervous system, cause liver damage and cancer. Mercury can cause heart related problems. In severe cases, mercury poisoning causes death by causing damage to the brain.

Q15) list the water purification processes. Describe any one of them.

Ans: the water purification processes are:

a) Boiling

b) Filtration

c) Sedimentation

d) Loading

e) Distillation

 * Filtration: this method is used to separate insoluble particles from water using a porous device.

Q16) what is eutrophication? How does it affect aquatic life?

Ans: the decomposing plants and aquatic organisms us up most of the oxygen presented in the water . As a result the water is left with very little dissolved oxygen. This process of enrichment of water with plant nutrients which leads to thick plant growth and depletion of oxygen level in water is called eutrophication.

Eutrophication result in the death of fish and other aquatic animals which depend on dissolved oxygen ultimately, the water body is left with very few life form. Such area are commonly called dead zones,