Question

When does the bottom of a lake not freeze in sever winter even when the surface is all frozen?

Answer 1

Due anomalous expansion of water the bottom of lake does freeze while surface is frozen.

Answer 2

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1. In cold countries, in winter, a layer of ice is formed on the surface of lakes when the atmospheric temperature falls below 0°C.

2. However, below this layer, there is water at 4°C.

3. Ice, being a bad conductor of heat, does not allow transfer of heat from this water to the atmosphere.

Hence, aquatic animals and plants can survive in this water. It is due to anomalous behavior of water.

Hope it helps!

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