Definition

1. Adjective:
   • (Of a physical system) continuing in its present state of equilibrium unless sufficiently disturbed to pass to a more stable state of equilibrium: This describes a condition that is stable for a period but is not in the lowest possible energy state; it will change if given enough energy or a sufficient disturbance.

Usage

• The term metastable is used primarily in physics and chemistry to describe systems, states, or phases.
• It describes a temporary or conditional stability. The system appears stable but is actually vulnerable to change.
• It is often used with nouns like , , , , or .

Examples

• Adjective:
  • Supercooled water is a metastable liquid; it remains liquid below 0°C until a seed crystal or disturbance triggers rapid freezing.
  • The excited atom was in a metastable state before it finally emitted a photon and returned to the ground state.
  • Diamond is metastable under ambient conditions because graphite is the more stable form of carbon.

Advanced Usage

• "Metastable equilibrium": A specific type of equilibrium that is stable to small disturbances but not to larger ones that can push the system into a more stable configuration.
  • The ball resting on a small hill is in a state of metastable equilibrium; a gentle nudge won't move it, but a strong push will send it rolling into the valley.

Variants and Related Words

• Metastability (noun): The property or condition of being metastable.
  • The metastability of the supersaturated solution was fascinating to observe.

Synonyms

• Unstable equilibrium: (Technical) A state that is stable only for small perturbations.
• Labile: (In chemistry) Prone to change or instability, though not an exact synonym.
• Transiently stable: Describing temporary stability.

Antonyms

• Stable: Firmly established and not likely to change.
• Unstable: Lacking stability and prone to immediate change.
• Ground state: (In physics) The lowest and most stable energy state of a system.

Adjective

1. (of physical systems) continuing in its present state of equilibrium unless sufficiently disturbed to pass to a more stable state of equilibrium