In physics, superheating (sometimes referred to as boiling retardation, boiling delay, or defervescence) is the phenomenon in which a liquid is heated to a temperature higher than its standard boiling point, without actually boiling. This can be caused by rapidly heating a homogeneous substance while leaving it undisturbed (so as to avoid the introduction of air bubbles at nucleation sites). A Superconductor demonstrating the Meissner Effect Physics (from the Greek, φυσικός (physikos), natural, and φύσις (physis), nature) is the science of the natural world dealing with the fundamental constituents of the universe, the forces they exert on one another, and the results produced by these forces. ... A liquid will assume the shape of its container. ... Temperature is the physical property of a system which underlies the common notions of hot and cold; the material with the higher temperature is said to be hotter. ... The boiling point of a substance is the temperature at which it can change its state from a liquid to a gas throughout the bulk of the liquid. ... It has been suggested that this article or section be merged with homogeneity. ... Aerosol pollution over Northern India and Bangladesh - NASA Cloud condensation nuclei or CCNs are small particles (typically 0. ...

Because a superheated fluid is the result of artificial circumstances, it is metastable, and is disrupted as soon as the circumstances abate, leading to the liquid boiling very suddenly and violently—a very dangerous situation. Superheating is sometimes a concern with microwave ovens, some of which can quickly heat water without physical disturbance. A person agitating a container full of superheated water by attempting to remove it from a microwave will likely be scalded. In the physical sciences, a phase is a set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties (i. ... A steam explosion (also called a littoral explosion, or fuel-coolant interaction, fci) is a violent boiling or flashing of water into steam, occurring when water is either superheated, or rapidly heated by fine hot debris produced within it. ... Microwave oven A microwave oven, (or microwave), is a kitchen appliance employing microwave radiation primarily to cook or heat food. ... Water (from the Old English word waeter; c. ... This page deals with the type of injury called burns; for other meanings of burn see burn (disambiguation) In medicine, a burn is a type of injury to the skin caused by heat, electricity, chemicals, or radiation (an example of the latter is sunburn). ...

More on Microwaving

Superheating is common when a person puts an undisturbed cup of water into the microwave and heats it. Once finished, the water appears to have not come to a boil. Once the water is disturbed, it violently comes to a boil. This can be simply from contact with the cup, or the addition of substances like instant coffee or sugar, which could result in hot scalding water shooting out. The chances of superheating is more common with smooth containers, such as brand-new glassware that lacks any scratches (scratches can house small pockets of air, which can serve as a nucleation point; that is not to say that an old container automatically is safe). To prevent this, adding something to the water, such as a wooden spatula/popsicle stick, prior to heating it is suggested; rotating dishes in modern microwave ovens can also provide enough perturbation and prevent superheating.

See also

• Supercooling
• Supersaturation
• Critical point
• Microwaving
• Autoclave

Supercooling is the process of chilling a liquid below its freezing point, without it becoming solid. ... HI JAMIE!!!!! In chemistry, the term supersaturation or oversaturation refers to a solution that contains more of the dissolved material than could be dissolved by the solvent under normal circumstances. ... Chemistry In chemistry, a critical point is the conditions ( temperature, pressure) at which the liquid state of the matter ceases to exist. ... It has been suggested that this article or section be merged with microwave oven. ... Front loading autoclaves are common Image:Autoclave cassette. ...

External links

• The physics of superheating water
• Video of superheated water in a microwave explosively flash boiling.
• A series of superheated water with oil film experiments done in the microwave by Louis A. Bloomfield, physics professor at the University of Virginia. Experiment #13 proceeds with surprising violence.
• Superheating and microwave ovens (video) Why it happens and why it's dangerous.