Mass action may refer to:
- Law of mass action, in chemistry, a postulate of reactions
- Mass action law (electronics), in semiconductor electronics, a relationship between intrinsic and doped carrier concentrations
- Mass action (sociology), in sociology, a term for situations in which a large number of people behave simultaneously in similar ways individually and without coordination
- Mass Action Principle (neuroscience), in neuroscience, the belief that memory and learning are distributed and can't be isolated within any one area of the brain
- Mass tort, or mass action, in law, which is when plaintiffs form a group to sue a defendant (for similar alleged harms)
Famous quotes containing the words mass and/or action:
“When over Catholics the ocean rolls,
They must wait several weeks before a mass
Takes off one peck of purgatorial coals,
Because, till people know what’s come to pass,
They won’t lay out their money on the dead—
It costs three francs for every mass that’s said.”
—George Gordon Noel Byron (1788–1824)
“Economic depression can not be cured by legislative action or executive pronouncement.”
—Herbert Hoover (1874–1964)