Before Heat is Transferred into the Sample:
Solid: In a solid, the particles (atoms or molecules) are tightly packed and held in a fixed position. They vibrate in place but do not have enough energy to break free from their fixed positions. The arrangement is orderly.
After Heat is Transferred into the Sample:
Solid: When heat is transferred into a solid, the particles absorb the thermal energy. As a result, they gain kinetic energy and start vibrating more vigorously. This increased movement causes the solid to expand slightly, but the particles remain in their fixed positions. The arrangement is still orderly.
Liquid: As heat is added to a solid and it reaches its melting point, it transforms into a liquid. In the liquid state, the particles have 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.
Gas: When even more heat is added to a liquid and it reaches its boiling point, it turns into a gas. In the gas state, the particles have gained a lot of energy and move rapidly in random directions. They are now far apart from each other, and the arrangement is highly disordered.
So, adding heat to a solid increases the kinetic energy of its particles, allowing them to vibrate more vigorously within their fixed positions. When heat is added beyond a certain point, the solid can change into a liquid and eventually a gas as the particles gain more energy and exhibit greater freedom of movement.