Before Heat is Transferred into the Sample:
Solid: In a solid, the particles are tightly packed and have very little kinetic energy. They vibrate in fixed positions but don't have enough energy to break free from their arrangement. The solid maintains a definite shape and volume.
After Heat is Transferred into the Sample:
Solid: When heat is added to a solid, the particles absorb the thermal energy. As a result, their kinetic energy increases, and they vibrate more vigorously within their fixed positions. This added energy causes the solid to expand slightly, but the particles remain in an orderly, closely-packed arrangement.
Liquid: If more heat is added, a solid can undergo a phase change into a liquid. In the liquid state, the particles have gained enough energy to break free from their fixed positions. They move more freely, sliding past each other. The arrangement becomes less orderly compared to a solid, and the liquid takes the shape of its container while maintaining a constant volume.
Gas: Further addition of heat can cause the liquid to evaporate and become a gas. In the gas state, the particles have gained even more energy and move rapidly in random directions. They are now widely separated from each other, and the arrangement is highly disordered. Gases expand to fill the entire volume of their container, taking both its shape and volume.
So, the addition of heat to a solid increases the kinetic energy of its particles, allowing them to vibrate more vigorously but still remain in their fixed positions. If more heat is added, the solid can transition into a liquid or a gas as the particles gain more energy and experience greater freedom of movement.