Question

why the ice freezes from top while it melt from bottom

Answer 1

When a glass of water is freezed formation of ice starts from the top layer but melting starts from the bottom.

Reason :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 they get freezes first.2.Whereas melting process depends the factor of pressure among the solid molecules of water. Since, the pressure at the bottom are under greater stress than the pressure at the surface. The heating processtends to decreases the pressure for the bottom layer by melting process and later on whole liquid melts.