Standard atomic weights

{
  "id": "MLC-T-CHM-011282",
  "term": "Standard atomic weights",
  "field": "Chemistry",
  "definition": "The weighted average of the relative atomic masses of all naturally occurring isotopes of an element, reflecting their isotopic abundances on Earth. These values are determined and periodically updated by the IUPAC Commission on Isotopic Abundances and Atomic Weights. They are dimensionless quantities, often expressed with several decimal places.",
  "subject": "Physical and Biophysical Chemistry",
  "see_also": [
    "relative atomic mass"
  ],
  "references": [
    "Green Book, 2nd ed., p. 94 (https://goldbook.iupac.org/files/pdf/green_book_2ed.pdf)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/standard-atomic-weights/"
}