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प्रश्न
What should be done if the clothes of a person catch fire accidentally? Why?
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उत्तर
- Cover the person in a rug or blanket and Roll him on the floor.
- This will cut off the air and put out the flames.
- A suitable fire extinguisher can also be chosen.
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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 |
Write ‘True’ or ‘False’ in front of following statement.
Atmospheric nitrogen is directly absorbed by the plants to form plant proteins.
What is greenhouse effect?
State four steps to be taken to control air pollution.
Tick (√) the correct alternative from the choice given for the following statement.
Rust is
Give a brief account of the discovery of air and the scientists involved.
A mixture has a variable composition. Give three other reasons why air is considered a mixture and not a compound.
Complete the statement given below by filling in the blank with the correct word/s from the word/s given below
____________ is an example of a pollutant present in the air.
List five activities that are possible due to the presence of air.
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.
