Chemical equilibrium, state of balance in which two opposing reversible chemical reactions proceed at constant equal rates with no net change in the system. For example, when hydrogen gas, H2,...

Le Châtelier's principle, chemical principle that states that if a system in equilibrium is disturbed by changes in determining factors, such as temperature, pressure, and concentration of com...

Statics, branch of mechanics concerned with the maintenance of equilibrium in bodies by the interaction of forces upon them (see force). It incorporates the study of the center of gravity (see...

Vertigo, sensations of moving in space or of objects moving about a person and the resultant difficulty in maintaining equilibrium. True vertigo, as distinguished from faintness, lightheadedne...

Tautomer, one of two or more structural isomers that exist in equilibrium and are readily converted from one isomeric form to another. Of the various types of tautomerism that are possible, tw...

Harmonic motion, regular vibration in which the acceleration of the vibrating object is directly proportional to the displacement of the object from its equilibrium position but oppositely dir...

Balance of power, system of international relations in which nations seek to maintain an approximate equilibrium of power among many rivals, thus preventing the preponderance of any one state....

Mannerism, a style in art and architecture (c.1520–1600), originating in Italy as a reaction against the equilibrium of form and proportions characteristic of the High Renaissance. In Florence...

Ear, organ of hearing and equilibrium. The human ear consists of outer, middle, and inner parts. The outer ear is the visible portion; it includes the skin-covered flap of cartilage known as t...

Common-ion effect, decrease in solubility of an ionic salt, i.e., one that dissociates in solution into its ions, caused by the presence in solution of another solute that contains one of the ...