Question

O
its of air and their approximate proportions.
gher proportion of carbon dioxide in air?
you expect a higher proportion of water vapour in air?
4. Name two major components of air ar
5. Is the composition of air strictly fixed?
6. Where would you expect a higher proportion of car
7. In which season would you expect a highe
8. Which gas is formed when carbon is burnt in air?
B. Answer the following in not more than 40 words.
1. Describe an activity to show that water contains air.
2. How would you show that a candle needs air to burn?
3. Of what use is the hair in your nostrils?
4. Mention five important uses of air.
C. Answer the following in not more than 100 words.
1. How would you prove that a so-called empty glass is not
glass is not empty? What does it contain?
2. How would you prove that air can cause the downward
can cause the downward displacement of water?
3. Describe how plants and animals depend on one anoth
animals depend on one another for oxygen and carbon dioxide.
D. Choose the correct option in each of the following.
1. Fish derive oxygen from
(a) water because it is a compound of hydrogen and oxygen
(b) the soil below water
(c) the dissolved air
(d) the atmospheric air
2. Air occupies space and has
(d) none of these
(a) colour
(b) smell
(c) mass
3. Which of the following constituents of air is used in photosynthesis?
(a) Nitrogen
(b) Oxygen
(c) Carbon dioxide
(d) Dust​

Answer 1

Answer:

here is your answer

Explanation:

4. nitrogen and oxygen

5.yes

8.carbondioxide

2. candle need oxygen to burn

3. to stop the dust particles

D-1. (a)

2.(c)

3.(c)

hope you have understood,

mark as brilliant...

Answer 2

Answer:

A continent is one of several large landmasses. Generally identified by convention rather than any strict criteria, up to seven regions are commonly regarded as continents. Ordered from largest in area to smallest, these seven regions are: Asia, Africa, North America, South America, Antarctica, Europe, and Australia.[1] Variations with fewer continents may merge some of these, for example some systems include Eurasia or America as single continents.the seven most globally recognized continents, only Antarctica and Australia are completely separated from other continents by the ocean.

Explanation:

A continent is one of several large landmasses. Generally identified by convention rather than any strict criteria, up to seven regions are commonly regarded as continents. Ordered from largest in area to smallest, these seven regions are: Asia, Africa, North America, South America, Antarctica, Europe, and Australia.[1] Variations with fewer continents may merge some of these, for example some systems include Eurasia or America as single continents.the seven most globally recognized continents, only Antarctica and Australia are completely separated from other continents by the ocean.