How does the arrangement of particles change during sublimation?

During sublimation, particles move from a closely packed solid state directly to a widely spread gaseous state without passing through the liquid phase.

Sublimation is a fascinating process that involves a substance changing from a solid to a gas without ever becoming a liquid. This process is a type of phase transition, or a change in the state of matter, that occurs under certain conditions of temperature and pressure.

In a solid, particles are tightly packed together in a fixed, orderly arrangement. They vibrate about fixed positions but do not move from place to place. This is why solids have a definite shape and volume. However, during sublimation, these particles gain enough energy to overcome the forces of attraction holding them together in the solid state.

As the solid substance heats up, the particles start to vibrate more and more. When the substance reaches its sublimation point, the particles have enough energy to break free from their fixed positions and move into the gas phase. In the gaseous state, particles are far apart and move randomly at high speeds. This is why gases fill their containers, taking on both the shape and volume of the container.

It's important to note that not all substances can sublimate. Sublimation occurs in substances like dry ice (solid carbon dioxide), iodine and naphthalene (mothballs) under normal atmospheric conditions. For other substances, sublimation can occur under specific conditions of low pressure.

In summary, the arrangement of particles during sublimation changes dramatically. They go from being tightly packed in a fixed, orderly arrangement in the solid state to being widely spread out and moving randomly in the gaseous state. This transition happens directly, bypassing the liquid phase entirely.