How do the particle in matter behave when a solid turns into a liquid?

Answer 1

Kinetic theory is the part of physics that houses the answer.

As temperature increases, particles move faster and faster. They gain more kinetic energy. In solids, molecules are tightly bound together (jiggling in only a miniscule fashion) but as they gain greater kinetic energy they have more potential to move past one another. They become less tightly bound and by the expression move past one another one can easily imagine such giving rise to the flow of liquids. Imagine the crystal structure of ice breaking down to liquid water as an easy example of this. But the principle would be the same in the production of all liquids. Liquid nitrogen flows too, as does glass. Imagine the wall forever moving on the molecular level - particles gaining speed and thus becoming less well bound together as temperature increases. And thus, moving faster and pushing past one another with their increased energy, the movement of the particles renders a solid......a liquid.

Answer 2

If you heat matter its atoms will start to vibrate and they will increase in volume. Because there is more space between the atoms, the matter will start to transform in a liquid.

Answer 3

The particles are "released" from their 'crystal' state, and the particles move much faster and more freely.

~me