Melting

Definition

Melting is the phase transition from a solid to a liquid. It occurs when a substance absorbs sufficient heat to overcome its molecular forces.

5 Must Know Facts For Your Next Test

1. The melting point is the specific temperature at which a solid becomes a liquid.
2. During melting, the temperature of the substance remains constant until all the solid has turned into liquid.
3. The energy required to change a solid at its melting point to a liquid is called the latent heat of fusion.
4. Impurities in a substance typically lower its melting point, causing it to melt over a range of temperatures rather than at one specific point.
5. Melting is an endothermic process, meaning it absorbs heat from its surroundings.

Review Questions

• What happens to the temperature of a substance during the melting process?
• How do impurities affect the melting point of a substance?
• What is the term for the amount of energy required to melt one mole of a solid at its melting point?

Related terms

Freezing:

The phase transition from liquid to solid; it occurs when a liquid loses enough heat.

Latent Heat of Fusion: The amount of energy required to convert one mole of a solid into its liquid state at constant temperature and pressure.

Endothermic Process: A process that absorbs heat from its surroundings.