Question

Can ice be made to sublimate? Is the reverse of sublimation also possible?

Answer 1

Yes, by reducing pressure over it so that external pressure becomes equal to vapor pressure of solid e.g., ice will sublimate on moon $(whereexternalpressure=0)$.The reverse of sublimation,i.e., conversion of vapors directly into solid is called 'Hoarfrost' and freezing of clouds to form snow is an example of it. Here it is worthy to note that the main difference between ice and snow is the fact that ice results from the conversion of the liquid into solid while snow from a conversion of vapors into solid.