The snow on the mountains does NOT melt all at once when it is heated by the sun because:
(1) it becomes very hard
(2) it reflects most of the heat from the sun
(3) it has a low specific heat capacity
(4) it has a high latent heat of fusion
Answer: (2) Newly formed snow reflects about 90 per cent of the sunlight that falls upon it. This means that the sun is powerless to melt clean snow. And when snow does melt, it is not because of the sunlight. Snow does not melt on a spring day because of the sun’s heat. It melts because of the warm air from the sea.
