What is the composition of a
2 which gas in the atmosphere is essental for spiration?
3. How will you prove that air supports burning
4. How will you show that air is assored in water?
5. Why does a lump of cotton wool shrink in water
Answers
Answer:
2.Oxygen gas in the atmosphere is essential for respiration.
3.Cover the burning candle with a glass jar. After few minutes the candle is extinguished. As the supply of air is stopped due to glass jar the burning of candle is also stopped. This experiment proves that air supports burning.
4.Heat it slowly on a tripod stand. Before the water begins to boil, look carefully at the inner surface of the vessel. You will see tiny bubbles on the inside. On heating, air dissolved in water escapes in the form of these bubbles.
5.A lump of cotton wool has a lot of air trapped inside the space present in its fibers. When this lump of cotton is immersed in water, all the air is replaced by water. Due to this, the cotton lump shrinks down.
Explanation: