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प्रश्न
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.
Why did the tiny bubbles appeared?
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उत्तर
The tiny bubbles appeared when the water started boiling because of the air dissolved in water. When she started boiling the water, the air that was dissolved in the water escaped in the form of bubbles.
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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:
oxygen
Tick (√) the correct alternative from the choice given for the following statement.
Air consists of
Describe a simple experiment with the help of a diagram to show that Air occupies space
State whether the following statement is true or false.
The pressure exerted by air is called atmospheric pressure.
Explain Lavoisier’s experiment which provided evidence to the discovery of components in air.
Take a squeezable bottle. Make a hole on the lid and close the bottle tightly. Bring the bottle near your face and press the bottle. What do you feel?
State whether the following statement is true or false. If false, correct them.
Air does not occupy any space.
A list of words is given in a box. Use appropriate words to fill up the blank in the following statement.
The ______ makes the windmill rotate.
Explain the following observations very briefly
A firki does not rotate in a closed area.
