Metastable

Definition

A metastable state is an excited state of an atom that has a longer lifetime than typical excited states. It delays returning to the ground state, often requiring external factors to prompt de-excitation.

5 Must Know Facts For Your Next Test

1. Metastable states are crucial in laser technology as they allow for population inversion.
2. The lifetime of a metastable state can range from microseconds to several minutes.
3. Metastable states often result from forbidden transitions, where direct decay is highly improbable.
4. They play a significant role in phenomena such as phosphorescence and certain types of fluorescence.
5. External stimuli like collisions or light absorption can induce transitions out of a metastable state.

Related terms

Ground State: The lowest energy state of an atom or molecule, where it is most stable.

Population Inversion:

A condition where more atoms are in an excited state than in lower energy states, essential for laser operation.

Phosphorescence:

A type of photoluminescence related to the delayed re-emission of absorbed energy due to transition through a metastable state.