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Given reasons (i) Lakes freeze form to...

Given reasons
(i) Lakes freeze form top towards bottom.
(ii) Ice floats on water.

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(a) The density of ice is less than that of liquid water. Therefore, ice floats on the surface. Thus, the ice layer at lower temperature floats over the water below it. Due to this the freezing of water into ice occurs continuously from top towards bottom.
(b)Since water expands on freezing, therefore, volume of ice for the same mass of water is more than liquid water. Hence mase per unit volume i.e., density of ice is lower than liquid water.
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