PSC-elementary-science-Solution of-chapter-four 2017

PSC Elementary Science: Solution of Chapter Four 2017

Air: this is the fourth chapter. This chapter tells us in detail about air. Like second and third chapter, this chapter is also easy and its length is small. It is very easy to learn. Like water, air is also an important element of the environment.
At a glance
1. Air in Daily Life.
2. Use of Wind
3. Use of Air
4. Causes of Air Pollution
5. Effects of Air Pollution on Human Health and The Environment
6. How to prevent Air Pollution

A student has to face some questions which are mandatory for her or him also. These are competency based questions. These will prove student’s creative skill. I think the first five chapters are more important for these mandatory competency based questions. I assure you that you will get one or two questions from these chapters. The previous questions of PSC exams also gave evidence of it. So, this chapter is urgent for you.

Short Answered Questions (Main Text)
1. How do people use wind in their daily life? ★
Ans: People use wind in their daily life.

  1. People use wind from a hand fan or electric fan to cool themselves.
  2. A boatman uses wind to travel across the river for his sailboat.
  3. Wind is used to dry something wet because it can take away water from something wet quickly. We hang out wet clothes in open place to dry them with the wind.
  4. We use a dryer to dry wet hair.

2. What are the negative effects of air pollution on human health?
Ans: Air pollution is harmful for human health. It can cause diseases such as lung cancer, respiratory infections, and heart disease.

3. Give three ways to prevent air pollution?
Ans: Three ways to prevent air pollution are given below:

  1. 1. Using less energy we can reduce more consumption of fossil fuel. For example, turning off the lights, and walking or riding bicycle instead of using car.
  2. We can also follow 3R’s like reducing use of natural resources, reusing, and recycling to prevent pollution.
  3. Cleaning garbage and planting trees are also good practices to help air clean.

4. What are the causes of air pollution?

Ans: Causes of air pollution are many.

  1. Human activity is a major cause of air pollution, especially the burning of fossil fuels.
  2.  It releases different types of gasses into the air. Those gasses come from factories, cars and landfills.
  3. The smoke from burning woods is the causes of air pollution too.
  4. Throwing garbage or urinating anywhere causes air pollution also.

Descriptive Questions (Main text)
1. We want to dry wet clothes as soon as possible but it is raining outside. How can we dry them quickly in our house? ★
Ans: When it is raining outside but we want to dry wet clothes as soon as possible, we need to hang out wet clothes in our house by using a rope. We use an electric fan to dry wet clothes quickly. Because the wind can take away water from something wet quickly.
2. How does recycling help to reduce air pollution? ★
Ans: Recycling helps to reduce air pollution. It reduces more consumption of fossil fuels. The burning of fossil fuels increases air pollution. It increases the amount of harmful gasses in the air. On the other contrary, recycling decreases the pressure on fossil fuels. It is nature friendly. So it helps to reduce air pollution.

3. What are the causes of air pollution? How do people pollute air?
Ans: Air pollution is the introduction of unwanted chemicals, gasses, dust particles, smoke or odour into the air. Human activity is a major cause of air pollution, especially the burning of fossil fuels. It releases different types of gasses come from factories, cars and landfills. The smoke from burning woods is the causes of air pollution too. Throwing garbage or urinating anywhere causes air pollution. These tasks are mainly done by people.

More questions
1. How do people use of wind to produce electricity?
Ans: Wind is used to move big wheels or blades of turbine to produce electricity.
2. How do people use air? ★
Ans: People use air to inflate something such as footballs, tyres of cars, bicycles and rickshaws. People also use the elements of air in different ways. Patients with breathing problems, divers, and alpinists are given oxygen from oxygen cylinder. People use nitrogen to make fertilizers called urea, and to preserve foods such as fish, meat, and chips in tins or packages. Carbon dioxide is used in soft drinks such as sodas to give it a fizz, and in fire extinguishers to put out fire.

3. How we use elements of air in different way? ★
Ans: People also use the elements of air in different ways.

    1. Patients with breathing problems, divers, and alpinists are given oxygen from oxygen cylinder.
    2.  People use nitrogen to make fertilizers called urea.
    3. People used nitrogen to preserve foods such as fish, meat, and chips in tins or packages.
    4. Carbon dioxide is used in soft drinks such as sodas to give it a fizz, and in fire extinguishers to put out fire.

4. Write the names of elements of air? ★

Ans. The elements of air  are oxygen, urea, and carbon dioxide.

Click here for Chapter Five: Energy and Matter

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