What are the starting and ended phases for sublimation?

Answer 1

Sublimation is the transition from solid directly to gas without passing through a liquid phase (e.g. dry ice is solid carbon dioxide at very low temperatures which sublimes into carbon dioxide gas).

Answer 2

The starting phase for sublimation is the solid phase, where a solid substance changes directly into a gas without passing through the liquid phase. The end phase of sublimation is the formation of a gas, as the substance transitions from a solid directly into a gas.