Tunnelling

{
  "id": "MLC-T-CHM-012361",
  "term": "Tunnelling",
  "field": "Chemistry",
  "definition": "The passage of a particle through a potential energy barrier that is classically insurmountable, meaning the barrier height exceeds the particle's kinetic energy. This quantum mechanical effect is a consequence of the wave-like nature of particles, where the wavefunction has a non-zero amplitude inside the barrier. The probability of tunnelling decreases exponentially with increasing barrier width and the square root of the particle's mass, making it most observable for electrons, protons, and deuterons.",
  "synonyms": [
    "quantum-mechanical tunnelling"
  ],
  "subject": "Organic and Biomolecular Chemistry",
  "see_also": [
    "isotopes",
    "potential-energy surface",
    "reduced mass"
  ],
  "references": [
    "PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1174 (https://doi.org/10.1351/pac199466051077)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/tunnelling/"
}