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प्रश्न
Tick (√) the correct alternative from the choice given for the following statement.
Air consists of
पर्याय
only oxygen
only nitrogen
only carbon dioxide
all of these
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उत्तर
all of these
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संबंधित प्रश्न
Match the statements in Column A, with those in Column B.
| Column A | Column B |
| 1. Largest Constituent of air, which dilutes the activity of oxygen. | (a) Oxygen |
| 2. A gas used for filling weather observeation balloons. | (b) Carbonic acid |
| 3. An acid formed by the dissolution of sulphur dioxide gas in water. | (c) Sulphuric acid |
| 4. An acid formed by the dissolution of carbon dioxide in water. | (d) Helium |
| 5. A gas vital for respiration. | (e) Nitrogen |
Give two uses of the following component present in air:
water vapour
Define the following:
Respiration
State two similarities and two differences between respiration and burning.
Tick (√) the correct alternative from the choice given for the following statement.
Fuels which do not leave any residue on burning are
State what do you understand by the term ‘air’. Explain its importance to mankind.
How is light scattered by the air?
The process of conversion of iron into hydrated form of oxides is called _______.
Match the items of Column I with the items of Column II
| Column I | Column II | ||
| (a) | Weather cock | (i) | Gases and fine dust particles |
| (b) | Mountaineers | (ii) | Sailing yacht |
| (c) | Fine hair inside the nose | (iii) | Oxygen cylinders |
| (d) | Smoke | (iv) | Direction of air flow |
| (e) | Wind | (v) | Prevent dust particles |
Paheli kept some water in a beaker for heating. She observed that tiny bubbles appeared before the water started to boil. She boiled the water for about 5 minutes and filled it in a bottle up to the brim and kept the bottle air tight till it cooled down to room temperature.
Do you think tiny bubbles will appear on heating the water taken out from the bottle? Justify your answer.
