* Melting is the process by which a solid changes into a liquid. This occurs when the temperature of the solid is raised to its melting point, the temperature at which it transitions from a solid to a liquid state. For example, when ice melts, it changes from a solid to a liquid state, water.
* Boiling is the process by which a liquid changes into a gas. This occurs when the temperature of the liquid is raised to its boiling point, the temperature at which it transitions from a liquid to a gas state. For example, when water boils, it changes from a liquid to a gas state, water vapor.
Both melting and boiling are endothermic processes, meaning they require energy in order to occur. This energy is used to break the intermolecular bonds between the molecules in the substance, allowing them to move more freely.
The reverse of melting is called freezing, which is the process by which a liquid changes into a solid. The reverse of boiling is called condensation, which is the process by which a gas changes into a liquid.
