Advertisements
Advertisements
प्रश्न
How do fishes and aquatic animals survive when the pond gets covered with thick ice?
Advertisements
उत्तर
Water has an unusual physical property. When cooled, it first contracts in volume, as do other liquids, but at 4°C (maximum density), it starts expanding, and continues to do so till the temperature reaches 0°C, the point at which it freezes into ice.
The property of anomalous expansion of water enables marine life to exist in the colder regions of the world, because even when the water freezes on the surface, it is still liquid below the ice layer.
APPEARS IN
संबंधित प्रश्न
Why is water essential for life?
Explain how the peculiar variation of density of water with temperature can cause water— pipes to burst in very cold places.
State whether the given statement are true or false. If true, write the reason.
Ganga−Brahmaputra plain of India is an overpopulated region.
Explain why rivers and lakes do not freeze easily.
Explain why:
Air dissolved in water contains a higher proportion of oxygen.
Unscramble the words and fill in the blanks.
- ondencsaonti ______
- vaeionorpat ______
- ecippitatrino ______
What is needed to construct a rain water harvesting pit?
________ of water is in oceans and seas.
“Every Drop Counts” is a slogan related to
Fill in the blanks in the following statements using words given in the box.
| air, handpumps, cholera, water, large, ground |
A very ______ number of our people defecate in the open. It may cause ______ pollution and soil pollution. Both the surface water and ______ water get polluted. ______ water is the source for wells, tubewells and ______. Thus it becomes the most common route for ______ borne diseases like ______, dysentery, etc.
