What happens to the particles of a solid when the solid changes into a gas?
they move faster.
they slow down.
they increase in size.
they decrease in size.

They move faster.

Explanation:

When a solid changes to gas, the process is called sublimation. This phase change increases the randomness of the particles as the heat increases i.e the entropy increases. For this phase change to occur, there must be an input of energy and this energy causes vibration of the particles and eventual increase in motion. The particles would then begin to move faster due to increase in kinetic energy.