Question

when a glass of water is fresh formation of ice starts from the top layer of melting of a starts from the bottom justify​

Answer 1

Answer:

Reasons for this phenomenon are:

1) Process of freezing depends on the movement of water molecule since the region of molecule present at surface are in direct contact with external cold condition so they freeze first.

2) Whereas melting process depends the factor of pressure among the solid molecules of water. Since, the pressure at the bottom are at under greater stress then the pressure at the surface. The heating process tends to decrease the pressure for the bottom layer by melting process and later on whole liquid melts.