Available Answers

1. 1.

   Choose the correct option.(MCQs)

   1. The gas present in air in greatest amounts is
      1. oxygen
      2. nitrogen
      3. carbon dioxide
      4. argon
   2. Which among the following processes is used for killing germs present in water?
      1. Evaporation
      2. Condensation
      3. Decantation
      4. Boiling
   3. Which is not based on air pressure?
      1. Sucking at a straw
      2. Using a dropper
      3. Inflating tyres of vehicles
      4. Cutting an apple
   4. Tick the statement not true about air.
      1. It is a matter.
      2. It cannot flow.
      3. It supports burning.
      4. It is a mixture of gases.
   5. Muddy water can be easily cleaned by
      1. boiling
      2. decantation
      3. sedimentation and decantation
      4. distillation
2. 2.

   Fill in the blanks using the right words from the help box.

   air pressure, soluble, matter, evaporation, distillation, chlorination

   1. Air is ________________ because it has mass and occupies space.
   2. ________________ is the ability of air to push.
   3. The process of converting a liquid into its vapours is called ________________.
   4. Sugar and salt are ________________ in water.
   5. ________________ is the process which involves boiling followed by condensation.
   6. ________________ kills germs present in water.
3. 3.

   Match the following:

   1. Distillation	a. Space between particles can be reduced
   2. Compressible	b. Required for photosynthesis
   3. Oxygen	c. A substance dissolved in a liquid
   4. Carbon dioxide	d. Separation of soluble substances
   5. Solution	e. Supports burning

    

4. 4.

   What is air made up of?

5. 5.

   Write the composition of different gases present in air.

6. 6.

   What is atmosphere?