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Subject:

science-chemistry

Class:

class VI

Key Concepts

atmosphere, carbon dioxide, composition of air, oxygen, nitrogen, smoke, windmill

essential questions

1. How does pollution lead to global warming?
2. How can change in composition of air lead to global warming?

Remembering:

  1. Name the various composition of air.
  2. Which of the following shows the direction of the wind: a) anemometer  b) windmill  c) windvane  d) barometer
  3. Which of the constituents of air on increasing causes global warming: a) nitrogen   b)oxygen  c)  inert gases  d) carbon dioxide
  4. The percentage of water vapor present in air is called: a) density  b) humidity  c) mass  d) solubility
  5. Breathing through mouth is not hygienic because: a) dust particles will enter our lungs   b) we will inhale more carbon dioxide  c) our throat will become sore  d) we will easily catch cold
  6. The correct ascending order of gases as per their composition in air is: a) oxygen < carbon di oxide < nitrogen   b) hydrogen < oxygen < nitrogen  c) nitrogen < hydrogen < oxygen  d) oxygen < carbon di oxide < hydrogen
  7. Which of the following is combustible: a) oxygen  b) nitrogen  c) water vapour  d) carbon dioxide

understanding:

  1. What is the role of fine hair present in our nostrils?
  2. Why is air called a mixture? Explain briefly.
  3. Which of the following processes need oxygen: a) combustion  b) respiration  c)  oxidation  d) all of the above
  4. Which of the statement is true regarding the earth’s atmosphere: a) it gets denser with an increase in the altitude   b)  it gets thinner with an increase in the altitude  c) it remains the same  d) contains no solid particles
  5. Which of the following plays a very important role in the oxygen cycle: a) birds  b) animals  c) plants  d) soil
  6. The proportion of oxygen and carbon dioxide in the atmosphere is maintained by: a) plants  b)  animals  c) machine  d) both a and b
  7. Air is: a) homogenous   b) heterogeneous   c) compound  d) alloy

Application:

  1. Why do mountaineers carry oxygen cylinder with them while climbing high mountains?
  2. How will you prove air supports burning?
  3. Why do we see earthworms only during rainy season outside the soil?
  4. How do we know there is air in soil? Explain with the experiment.
  5. In case of fire, one is advised to to wrap a woolen blanket around the object. Explain why.
  6. Why does a lump of cotton wool shrink when dipped in water?
  7. How do plants and animals help each other in exchange of gases in the atmosphere?
  8. Which of the following enables us to drink liquid through a straw: a) humidity  b) temperature  c) atmospheric pressure  d) composition of air

Analysis:

  1. Why do you see air bubbles forming in tub of water when we tilt an empty bottle inside the tub filed wit water? Give reasons.
  2. How do we know air has oxygen present in it? Explain in detail.
  3. What will happen to the candle when the glass is put on top of it. Do the water level rise or not. Give reasons for your answer and explain with a diagram.
  4. Air is dissolved in water. How can we explain this statement?
  5. When water begins to boil, we see tiny bubbles forming in the water. What are these bubbles? Can we see these bubbles when this boiled water is kept in a air tight container and re heated? Give reasons for your answer.
  6. Read the two sentence given in the box: Statement1: The compressed air in a tyre exerts force large enough to lift a heavy car  Statement 2: In a syringe, the plunger compressed the liquid  a) both statement 1 and 2 are correct   b) both statements 1 and2 are false   c) statement 1 is correct but statement 2 is false   d)  statement 1 is false but statement 2 is correct
  7. Statement 1: Mountain climbers require to carry oxygen cylinders. Statement 2: Oxygen levels decrease as we go higher and pressure also increase. a) both statement 1 and 2 are correct   b) both statements 1 and2 are false   c) statement 1 is correct but statement 2 is false   d)  statement 1 is false but statement 2 is correct
  8. In this experiment the following conclusion was drawn: Statement1: Air has mass. Statement 2: Balloon with air has more mass than the balloon with no air a) both statement 1 and 2 are correct   b) both statements 1 and2 are false   c) statement 1 is correct but statement 2 is false   d)  statement 1 is false but statement 2 is correct

Evaluation:

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