How does the particle model explain changes of state?

The particle model explains changes of state as a result of changes in energy and particle movement.

The particle model, also known as the kinetic theory of matter, is a fundamental concept in chemistry that describes the behaviour of particles in different states of matter. It explains changes of state - solid, liquid, gas, and plasma - as a result of changes in energy and particle movement.

In a solid, particles are closely packed together in a fixed, regular pattern. They vibrate in place but do not move from their positions because they have low energy. When a solid is heated, the particles gain energy and start to vibrate more. This increased vibration weakens the forces holding the particles together, causing the solid to melt and become a liquid. This is known as melting or fusion.

In a liquid, particles are still close together but can move around each other because they have more energy than in a solid. When a liquid is heated, the particles gain even more energy and start to move faster. This increased movement can overcome the forces of attraction between the particles, causing the liquid to evaporate and become a gas. This is known as vaporisation.

In a gas, particles are far apart and move freely in all directions because they have a lot of energy. When a gas is cooled, the particles lose energy and start to slow down. This decreased movement allows the forces of attraction between the particles to pull them closer together, causing the gas to condense and become a liquid. This is known as condensation.

Finally, if a solid is heated enough, it can skip the liquid state and go directly to the gas state. This is known as sublimation. Similarly, a gas can be cooled enough to skip the liquid state and go directly to the solid state. This is known as deposition.

In summary, the particle model explains changes of state as a result of changes in energy and particle movement. The more energy particles have, the faster they move and the further apart they are, which determines their state of matter.