Advertisements
Advertisements
प्रश्न
Give a brief account of the discovery of air and the scientists involved.
Advertisements
उत्तर
- John Mayow (1674) proved air has two components – active and inactive components.
- Lavoisier (1789) named the active component as oxygen and inactive component as nitrogen
- Other scientists (1800's) discovered noble gases, \[\ce{CO2}\], water vapours.
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 |
How is greenhouse effect produced?
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 observation balloons. | (b) carbon acid |
| 3. An acid formed by the dissolution of sulphur dioxide gas in water. | (c) Sulphur acid |
| 4. An acid formed by the dissolution of carbon dioxide in water. | (d) Helium |
| 5. A gas vital for respiration. | (e) Nitrogen |
State what do you understand by the term ‘air’. Explain its importance to mankind.
Fill in the blank:
Nitrogen of the air is utilized by plants for formation of _____.
About 78% of the volume of air is ______.
Which of the following statements is incorrect?
In a number of musical instruments, air plays an important role. Can you name some such instruments?
In the boxes of Column, I the letters of some words got jumbled. Arrange them in proper form in the boxes given in Column II
| Column I | Column II | ||
| (a) | \[\boxed{\text{D}}\]\[\boxed{\text{I}}\]\[\boxed{\text{L}}\]\[\boxed{\text{L}}\]\[\boxed{\text{M}}\]\[\boxed{\text{W}}\]\[\boxed{\text{I}}\]\[\boxed{\text{N}}\] | (a) | `squaresquaresquaresquaresquaresquaresquare square` |
| (b) | \[\boxed{\text{Y}}\]\[\boxed{\text{N}}\]\[\boxed{\text{O}}\]\[\boxed{\text{G}}\]\[\boxed{\text{X}}\]\[\boxed{\text{E}}\] | (b) | `squaresquaresquaresquaresquare square` |
| (c) | \[\boxed{\text{M}}\]\[\boxed{\text{E}}\]\[\boxed{\text{S}}\]\[\boxed{\text{K}}\]\[\boxed{\text{O}}\] | (c) | `squaresquaresquaresquaresquare` |
| (d) | \[\boxed{\text{T}}\]\[\boxed{\text{U}}\]\[\boxed{\text{D}}\]\[\boxed{\text{S}}\] | (d) | `squaresquaresquare` |
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.
