Melting

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Melting

Melting (sometimes called fusion) is a process that results in the phase change of a substance from a solid

Solid

A solid object is in the states of matter characterized by resistance to deformation and changes of volume. In other words, it has high values both of Young's modulus and of shear modulus; this contrasts e.g....
to a liquid

Liquid

Liquid is one of the principal states of matter. A liquid is a fluid that has the particles loose and can freely form a distinct surface at the boundaries of its bulk material....
. The internal energy of a solid substance is increased (typically by the application of heat or pressure) to a specific temperature (called the melting point

Melting point

The melting point of a solid is the temperature range at which it changes states of matter from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium....
) 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.

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Molecular vibrations

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

Constant temperature

Substances melt at a constant temperature, the melting point

Melting point

The melting point of a solid is the temperature range at which it changes states of matter from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium....
. 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

Gibbs free energy

In thermodynamics, the Gibbs free energy is a thermodynamic potential that measures the "useful" or process-initiating Work obtainable from an isothermal, Isobaric process thermodynamic system....
of the Material is zero, because the enthalpy

Enthalpy

In thermodynamics and chemistry, the enthalpy is a quotient or description of thermodynamic potential of a system, which can be used to calculate the heat transfer during a quasistatic process taking place in a closed system thermodynamic system under constant pressure....
and the entropy

Entropy

In many branches of science, entropy is a measure of the disorder of a system. The concept of entropy is particularly notable as it is applied across physics, information theory and mathematics....
of the material are increasing . 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:

The "","", and "" 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
Hagen Kleinert

Hagen Kleinert is Professor of Theoretical Physics at the Free University of Berlin, Germany , Honorary Professor at the Kyrgyz-Russian Slavic University, and Honorary Member of the ....
, Gauge Fields in Condensed Matter, Vol. II, "STRESSES
Stress (physics)

In continuum mechanics, stress is a measure of the average amount of force exerted per unit area. It is a measure of the intensity of the total internal forces acting within a body across imaginary internal surfaces, as a reaction to external applied forces and body forces....
AND DEFECTS
Defect

Defect, Defects, or defected may refer to:* Defect , a characteristic of a polyhedron* The Defects, Northern-Irish punk rock band...
; Differential Geometry, Crystal Melting", pp. 743-1456, World Scientific (Singapore, 1989); Paperback ISBN 9971-5-0210-0 (readable online )

Other meanings

In genetics

Genetics

Genetics , a discipline of biology, is the science of heredity and Genetic variation in living organisms. The fact that living things inherit traits from their parents has been used since prehistoric times to improve crop plants and animals through selective breeding....
, melting DNA

DNA

Deoxyribonucleic acid is a nucleic acid that contains the genetics instructions used in the development and functioning of all known living organisms and some viruses....
means to separate the double-stranded DNA into two single strands by heating or the use of chemicals.

See also : Polymerase chain reaction

Polymerase chain reaction

The polymerase chain reaction is a technique widely used in molecular biology. It derives its name from one of its key components, a DNA polymerase used to amplify a piece of DNA by in vitro enzyme DNA replication....

Ice
Ice

Ice is a solid phases of matter, usually crystalline solid, of a non-metallic substance that is liquid or gas at room temperature, such as ammonia ice or methane ice....
Melting point
Melting point

The melting point of a solid is the temperature range at which it changes states of matter from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium....
List of elements by melting point
List of elements by melting point

File:Element PhasesPerTemperature EN.svgThis is a list of the chemical elements, sorted by melting point measured at normal pressure....
Phase diagram
Phase diagram

A phase diagram in physical chemistry, mineralogy, and materials science is a type of Graph of a function used to show conditions at which thermodynamically-distinct phase can occur at thermodynamic equilibrium....
Phase transition
Phase transition

In thermodynamics, a phase transition is the transformation of a thermodynamic system from one phase to another.At phase-transition point, physical properties may undergo abrupt change- for instance, volume of the two phases may be vastly different....

	Solid Solid A solid object is in the states of matter characterized by resistance to deformation and changes of volume. In other words, it has high values both of Young's modulus and of shear modulus; this contrasts e.g....	Liquid Liquid Liquid is one of the principal states of matter. A liquid is a fluid that has the particles loose and can freely form a distinct surface at the boundaries of its bulk material....	Gas Gas In physics, a gas is a state of matter, consisting of a collection of particles without a definite shape or volume that are in more or less random motion....	Plasma Plasma (physics) In physics and chemistry, plasma is a partially ionized gas, in which a certain proportion of electrons are free rather than being bound to an atom or molecule....
From	To
Solid	N/A	Melting Melting 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 to a specific temperature at which it changes to the liquid phase....	Sublimation	-
Liquid	Freezing Freezing In physical science, freezing or solidification is the process in which a liquid turns into a solid when cold enough. The Melting point is the temperature at which this happens....	N/A	Boiling Boiling Boiling, a type of phase transition, is the rapid vaporization of a liquid, which typically occurs when a liquid is heated to its boiling point, the temperature at which the vapor pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding environmental pressure.... /Evaporation Evaporation Evaporation is the slow vaporization of a liquid and the reverse of condensation. A type of phase transition, it is the process by which molecules in a liquid State of matter spontaneously become gaseous ....	-
Gas	Deposition Deposition (physics) Deposition is a Thermodynamic process in which gas transforms into solid . The reverse of deposition is sublimation .One example of deposition is the Process by which, in sub-freezing air, water vapor changes directly to ice without first becoming a liquid....	Condensation Condensation Condensation is the change of the physical state of aggregation of matter from gaseous phase into liquid phase. When the transition happens from the gaseous phase into the solid phase directly, bypassing the liquid phase the change is called Deposition , which is the opposite of sublimation....	N/A	Ionization Ionization Ionization is the physics process of converting an atom or molecule into an ion by adding or removing charged particles such as electrons or other ions....
Plasma	-	-	Recombination/Deionization	N/A