What is the action of ice evaporating into air?

Answer 1

Water remains a constant homogeneous mixture regardless of its shape. During sublimation H2O in the form of ice just changes to a liquid then to a gas form; It can not go between ice and gas without turning into liquid. Heat must be present in this reaction.

Answer 2

Any solid evaporating is called sublimation.

The sublimation rate of ice depends on the temperature of the ice.

Virtually all substance exhibit some sublimation. Even diamonds are steadily evaporating (at a very very very slow rate that is not easily noticeable over thousands of years).