Static Equilibrium
A state of no change in which the opposing processes have genuinely ceased rather than balancing.
Unit
Dimensionless
In depth
Static equilibrium describes mechanical balance, not chemical systems: once an irreversible reaction reaches completion nothing further happens in either direction. The distinction matters because chemical equilibrium looks static from the outside while remaining intensely dynamic within.
Examples in the real world
A book resting on a table is in static equilibrium; a sealed bottle of soda water is in dynamic equilibrium.