Puhkeolek

Puhkeolek is the Estonian term for an excited state, a quantum state of higher energy than the ground state. It describes conditions in atoms, molecules, or atomic nuclei in which electrons, vibrational modes, or rotational modes carry more energy than in the lowest-energy configuration.

Excitation occurs when a system absorbs energy, such as light, electrical energy, or chemical energy from reactions. This energy transfer promotes one or more electrons to higher electronic orbitals or increases vibrational or rotational energy levels in a molecule, creating a puhkéolek.

Excited states are typically unstable and will relax to lower-energy states over time. Radiative decay emits energy as photons (fluorescence or phosphorescence in chemical systems, gamma rays in nuclear states). Non-radiative pathways include internal conversion, vibrational relaxation, or quenching by the surrounding environment. The lifetime of an excited state varies widely, from femtoseconds to milliseconds or longer for certain metastable states. Transition probabilities and lifetimes depend on selection rules and the local environment.

Types of excited states include electronic excited states (electrons promoted to higher orbitals) and vibrational or rotational excited states in molecules. Metastable states are those with comparatively long lifetimes. In nuclei, excited states are formed after reactions and decay via gamma emission.

Applications and significance include spectroscopy, which probes energy levels through emitted or absorbed light; lasers, which rely on stimulated emission from excited states; and photochemistry and materials science, where excited-state processes drive reactions and properties.