Advertisements
Advertisements
प्रश्न
How do fishes and aquatic animals survive when the pond gets covered with thick ice?
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
How are natural springs of water formed ?
Give a reason why alcohol and water form a miscible mixture while oil & water do not.
Select the correct answer of the following statement:
A decahydrate crystal.
State the meaning of the term ‘water pollution’. State how you would find out, the different sources of pollution of water bodies in the locality.
Explain why oil spills have an adverse effect on marine life.
_____ is a type of rainwater harvesting.
Which state government made rain water harvesting mandatory in the year 2001?
A mixture (x) in water contains suspended solids, organic impurities, inorganic impurities (a), nutrients (b), disease-causing bacteria and other microbes. Give names for (x), (a) and (b)?
Think and suggest some ways to minimise waste and pollutants at their source, taking your home as an example.
Look at Fig. 14.1.
Write down activities shown in this figure in which water is being used.
