Page 134 - ICSE Chemistry 6

19. Observe the given image carefully and answer the following ques ons.

(a) What does the image represent?
(b) Why is it that the water level is lower as compared to the water outside when the tumbler is turned
upside down in a trough of water?
(c) What happens on l ng the glass tumbler?

20. Rehaan has been asked to discuss the evidences that air is a mixture. He states the following evidences.
However as per the teacher these are incorrect. Iden fy the errors in the evidences stated by Rehaan.
• The composi on of air is constant everywhere. It remains same at all places and at all mes. The
composi on of air at higher al tudes and in plains is the same.

• There is a release of heat when the cons tuents of air are mixed together.
• The proper es of air are totally diff erent from those of its cons tuents.

• Air is represented using a defi nite formula.
• The components of air cannot be separated using simple physical methods.

21. What is the role of dust par cles present in the atmosphere?

22. Food + Oxygen  Energy + Water + Carbon dioxide
Which process is shown by the given equa on? Explain the process.

23. Do plants respire? How can you show respira on in plants?

24. Sunlight + Water + Carbon dioxide Chlorophyll Food + Oxygen
Which process is shown by the given equa on? Explain the process. What is the signifi cance of this
process?

25. ‘Air pollu on can lead to various health problems.’ Jus fy. How can you think this can be prevented?

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