during which change of state would the volume of a substance increase the most? deposition melting vaporization sublimation

The volume of a substance would increase the most during sublimation, which is the change of state from solid directly to gas. This is because the substance moves from a highly compact solid state to a widely spaced gas state, skipping the liquid phase and resulting in a dramatic volume increase. Vaporization (liquid to gas) also increases volume significantly but not as much as sublimation since sublimation starts from the solid's lower volume state. Deposition (gas to solid) and melting (solid to liquid) involve volume decreases or smaller volume increases respectively.