why fishes can breathe when upper layer is freeze,although  oxygen cannnot pass through solid?

Asked by nisha_vini29 | 10th May, 2015, 08:50: PM

Expert Answer:

Water boils at 100 degree Celsius (100 °C) and freezes at 0 °C. When the outside temperature falls below the freezing point of water, lakes and rivers get frozen. However, only the top layer of the lake or river freezes. Underneath the frozen upper layer, the water remains in its liquid form and does not freeze. Also, oxygen is trapped beneath the layer of ice. As a result, fish and other aquatic animals find it possible to live comfortably in the frozen lakes and ponds. Generally, all liquids expand on heating, but water is an exception to this rule. This irregular expansion of water is called anomalous expansion. This anomalous expansion plays an important role by only freezing the upper layer in lakes and rivers.

Answered by Arvind Diwale | 11th May, 2015, 10:49: AM