Boiling delay
physics, superheating (sometimes referred to as boiling delay) 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 extreme pressure elevating the boiling point (by forcing the molecules together more strongly, so that more energy is needed to separate them), or by rapidly heating a homogeneous substance while leaving it undisturbed (so as to avoid the introduction of air bubbles as nucleation sites).
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.
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