The change of state shown in the model is likely sublimation.
In this scenario, the left cylinder has balls (representing particles) stacked near the bottom, indicating a denser, solid form. The right cylinder shows the balls evenly spaced throughout, representing a gas state where the particles are much more spread out. Sublimation is the process where a solid changes directly into a gas without passing through a liquid state, which aligns with the transition from the tightly stacked configuration to a more spread-out arrangement.
If the model visually represents a solid transitioning to a gas, sublimation is the correct term. If there’s any specific context or visual that suggests otherwise, please provide further details for clarification.