Available Answers

1. 1.

   Multiple Choice Questions (MCQs). The (√) the right option:

   1. Air helps in burning. The active component of air is
      1. Carbon-dioxide
      2. Oxygen
      3. Nitrogen
      4. Argon
   2. Air pressure is maximum
      1. At sea level
      2. In plains
      3. On hills
      4. Same at all places
   3. In air the ratio of oxygen and nitrogen is approximately
      1. 5 : 1
      2. 4 : 1
      3. 1 : 5
      4. 4 : 5
   4. __________ is an universal solvent.
      1. Air
      2. Water
      3. Soil
      4. None of these
   5. 78% of air is
      1. Mesosphere
      2. Nitrogen
      3. Oxygen
      4. None of these
2. 2.

   Fill in the blanks with the given words:

   solvent

   burning

   air

   mixture

   harmful

   1. Polluted air is __________ to health.
   2. Air is a __________ of gases.
   3. Water is a very good __________.
   4. Oxygen helps in __________.
   5. __________ is essential for life.
3. 3.

   Write 'T' for true or 'F' for false:

   1. Oxygen is the active part of the air.
   2. Water ia the universal solvent.
   3. Carbon-dioxide is used for burning.
   4. Oxygen is a useful gas for green plants.
   5. Water can be purified by boiling.
4. 4.

   Match the following:

   1. Air	a. Barometer
   2. Air pressure	b. Is present everywhere
   3. Wind Vane	c. part of each which contains water
   4. Hydrosphere	d. A solute
   5. sugar	e. Shows the direction of the wind

    

5. 5.

   What do you mean by atmosphere? Name various layers of the atmosphere.
6. 6.

   What is air? Name all the gases present in it.