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:
“After the planet becomes theirs, many millions of years will have to pass before a beetle particularly loved by God, at the end of its calculations will find written on a sheet of paper in letters of fire that energy is equal to the mass multiplied by the square of the velocity of light. The new kings of the world will live tranquilly for a long time, confining themselves to devouring each other and being parasites among each other on a cottage industry scale.”
—Primo Levi (1919–1987)
“Make the expectations lively enough, and action will follow.”
—Mason Cooley (b. 1927)