Barn

{
  "id": "MLC-T-CHM-001114",
  "term": "Barn",
  "field": "Chemistry",
  "definition": "A non-SI unit of area used to express the effective cross-sectional area of a target nucleus in nuclear and particle physics. One barn is defined as exactly 10⁻²⁸ square meters, which is roughly the cross-sectional area of a uranium nucleus. The unit provides a convenient measure for the probability of a specific interaction, such as neutron capture or scattering, between an incident particle and a target nucleus.",
  "subject": "Physical and Biophysical Chemistry",
  "references": [
    "Green Book, 2nd ed., p. 75 (https://goldbook.iupac.org/files/pdf/green_book_2ed.pdf)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/barn/"
}