Physics – 2.1.1 States of matter | e-Consult

(a) Melting is the change of state from a solid (ice) to a liquid (water). Boiling is the change of state from a liquid (water) to a gas (steam).

(b)

• Melting: In a solid, water molecules are arranged in a fixed, ordered structure with limited movement. During melting, the molecules gain energy, allowing them to overcome the forces holding them in place. They become more disordered and can move more freely, transitioning into a liquid state.
• Boiling: In a liquid, water molecules are still relatively close but can move past each other. During boiling, the molecules gain sufficient energy to completely overcome the intermolecular forces. They escape from the liquid phase and become a gas, moving rapidly and randomly.