Extent

{
  "id": "MLC-T-CHM-004263",
  "term": "Extent",
  "field": "Chemistry",
  "definition": "A surface quantity measured by its area, with the real area of a rough solid distinguished from the geometric area, which is the projection of the surface onto a plane parallel to the visible phase boundary. In thermodynamics the word is also used for the extent of reaction, symbol xi, whose change is dxi = dn(i) / nu(i), measured in moles.",
  "subject": "Physical and Biophysical Chemistry",
  "see_also": [
    "roughness factor",
    "visible"
  ],
  "references": [
    "PAC, 1986, 58, 437. 'Interphases in systems of conducting phases (Recommendations 1985)' on page 439 (https://doi.org/10.1351/pac198658030437)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/extent/"
}