Effervescence

Effervescence is the rapid escape of gas from a liquid or solid, resulting in the formation of bubbles that rise through the medium. The term comes from the French effervescence, deriving from Latin effervescere, meaning to boil up.

In liquids, effervescence occurs when dissolved gas comes out of solution as conditions change. Gas solubility generally decreases with increasing temperature or decreasing pressure; for example, carbonated beverages keep carbon dioxide dissolved under pressure and release it when the container is opened. Effervescence also arises during chemical reactions that produce gas, such as the reaction of an acid with a carbonate that releases carbon dioxide.

The rate and appearance of effervescence depend on factors such as temperature, pressure, agitation, surface area, and the presence of nucleation sites or surface-active substances. Small bubbles may form a steady foam or simply rise and burst. Substances that promote or suppress bubble formation can influence the intensity of effervescence.

In everyday language, effervescence can describe a lively, bubbly personality, and in chemistry it is a straightforward observable of gas evolution.