What happens to particle motion as a solid turns to liquid?

As a solid turns to liquid, the particle motion increases, leading to more freedom of movement.

In a solid state, particles are tightly packed together in a fixed, regular pattern. They vibrate around a fixed point but do not move from place to place. This is because the forces of attraction between the particles are strong enough to hold them in place. The solid has a definite shape and volume because of this fixed arrangement of particles.

However, as the solid is heated and begins to turn into a liquid, the particles gain more kinetic energy. This energy allows them to overcome some of the forces of attraction holding them together. As a result, the particles start to move more freely, sliding past each other. This increased motion and freedom is what changes the solid into a liquid. The liquid state has a definite volume but can change shape to fill the bottom of a container, reflecting the increased movement of its particles.

It's important to note that the transition from a solid to a liquid doesn't happen all at once. It's a gradual process that occurs over a range of temperatures, known as the melting point. During this phase change, the temperature remains constant even though energy is still being added. This is because the energy is used to break the forces of attraction between the particles, rather than increase their kinetic energy. Once all the solid has melted into a liquid, any additional energy will then increase the temperature of the liquid and the particles will move even faster.

In summary, the transition from a solid to a liquid involves an increase in particle motion, as the particles gain kinetic energy and start to move more freely. This change in motion is what allows the substance to change from a fixed, rigid shape to a more fluid one.