melt n : the process whereby heat changes something from a solid to a liquid; "the power failure caused a refrigerator melt that was a disaster"; "the thawing of a frozen turkey takes several hours" [syn: thaw, thawing, melting]

1 reduce or cause to be reduced from a solid to a liquid state, usually by heating; "melt butter"; "melt down gold"; "The wax melted in the sun" [syn: run, melt down]

2 become or cause to become soft or liquid; "The sun melted the ice"; "the ice thawed"; "the ice cream melted"; "The heat melted the wax"; "The giant iceberg dissolved over the years during the global warming phase"; "dethaw the meat" [syn: dissolve, thaw, unfreeze, unthaw, dethaw]

3 become more relaxed, easygoing, or genial; "With age, he mellowed" [syn: mellow, mellow out]

4 lose its distinct outline or shape; blend gradually; "Hundreds of actors were melting into the scene" [syn: meld]

5 become less clearly visible or distinguishable; disappear gradually or seemingly; "The scene begins to fade"; "The tree trunks are melting into the forest at dusk" [syn: fade]

6 become less intense and fade away gradually; "her resistance melted under his charm" [syn: disappear] [also: molten]molten adj : reduced to liquid form by heating; "a mass of molten rock" [syn: liquefied, liquified]molten See melt

English

Pronunciation

• Rhymes: -əʊltən

Adjective

1. Melted.

   molten wax

   molten rock

2. made from molten substance
3. glowing red-hot

Translations

Verb

molten

1. past participle of melt

Melting is a process that results in the phase change of a substance from a solid to a liquid. The internal energy of a solid substance is increased (typically by the application of heat) to a specific temperature (called the melting point) at which it changes to the liquid phase. An object that has melted completely is molten.

The melting point of a substance is a characteristic property. The melting point may not be equal to the freezing point. This is evident in the phenomenon known as supercooling. In the case of water, ice crystals typically require a seed on which to begin formation. Water on a very clean glass surface will often supercool several degrees below the melting point without freezing. Fine emulsions of pure water have been cooled to -38 degrees celsius without the nucleation of ice taking place. For this reason, melting point is a characteristic property of a substance while freezing point is not.

Molecular vibrations

When the internal energy of a gas is increased by the application of an external energy source, the molecular vibrations of the substance increases. As these vibrations increase, the substance becomes more and more ordered. Fusion is also another term used for this.

Constant temperature

Substances melt at a constant temperature, the melting point. Further increases in temperature (even with continued application of energy) do not occur until the substance is molten.

The thermodynamics of melting

From a thermodynamics point of view, at the melting point the change in Gibbs free energy (\Delta G) of the Material is zero, because the enthalpy (H) and the entropy (S) of the material are increasing (\Delta H, \Delta S > 0). Melting phenomenon happens when the Gibbs free energy of the liquid becomes lower than the solid for that material. At various pressures this happens at a specific temperature. It can also be shown that:

\Delta S = \frac

The "T","\Delta S", and "\Delta H" in the above are respectively the temperature at the melting point, change of entropy of melting, and the change of enthalpy of melting.

Books

• Kleinert, Hagen, Gauge Fields in Condensed Matter, Vol. II, "STRESSES AND DEFECTS; Differential Geometry, Crystal Melting", pp. 743-1456, World Scientific (Singapore, 1989); Paperback ISBN 9971-5-0210-0 (readable online here)

Other meanings

In genetics, melting DNA means to separate the double-stranded DNA into two single strands by heating or the use of chemicals.

See also : Polymerase chain reaction

See also

• Ice
• Melting point
• List of elements by melting point
• Phase diagram
• Phase transition