You have drawn a diagram of the particles, but what do we mean by particles? We have used the term ‘particles’ very deliberately, because it’s somewhat ambiguous. In the case of water, it will be molecules of  but with other substances they could be single atoms.

• In a solid the particles are in fixed locations, but they vibrate. They are tightly packed together.
• In a liquid the particles are free to move, but are still touching each other. A liquid is less ordered than a similar solid. They will fill a container from the bottom up.
• In a gas the particles are free to move around, and are much more spread out. They move quickly, and randomly collide with each other and the container walls.

A phase change or state change occurs when a substance changes from one state to another. The state changes we consider are melting, boiling, condensing, solidifying, sublimation and evaporation.