{
  "name": "Two routes to the size of an atom: radius tables and density",
  "desc": "Inputs and results of both routes: tabulated diameters of gold, and the room one atom or ion takes in gold, salt and liquid water from density, weight and the Avogadro constant, with salt's crystal cell edges as a check.",
  "lic": "CC BY 4.0",
  "lic_url": "https://creativecommons.org/licenses/by/4.0/",
  "by": "Ants, Cells & Atoms",
  "url": "https://antscellsandatoms.com/scale/atom-size/",
  "from": [
    "PubChem element record 79, Density and Atomic Weight sections (saved responses, 2026-10-25)",
    "PubChem CID 5234, Density, Molecular Weight and Crystal Structures sections (saved responses, 2026-10-25)",
    "PubChem CID 962, Molecular Weight section (saved response, 2026-10-25)",
    "media/water-properties.csv (shared file; 25 °C and 4 °C density rows)",
    "CODATA 2022 Avogadro constant (saved constant page, 2026-10-25)"
  ],
  "how": "Compiled by Ants, Cells & Atoms from the data listed",
  "data_by": [
    "PubChem element records 1–96, Atomic Radius section, PubChem 2025 update, https://doi.org/10.1093/nar/gkae1059 (covalent radii from Cordero B et al. 2008, Dalton Transactions, https://doi.org/10.1039/b801115j; empirical radii from Slater JC 1964, The Journal of Chemical Physics, https://doi.org/10.1063/1.1725697; van der Waals radii from the Los Alamos National Laboratory periodic table; retrieved 2026-10-25)",
    "PubChem element record 79 (Gold), PubChem 2025 update, https://doi.org/10.1093/nar/gkae1059: density 19.282 g/cm3 (credited to Jefferson Lab; no temperature given) and standard atomic weight 196.966570(4) (IUPAC Commission on Isotopic Abundances and Atomic Weights), retrieved 2026-10-25; gold's van der Waals radius, 166 pm, equals Bondi's 1964 value, Bondi A 1964, The Journal of Physical Chemistry 68(3):441–451, https://doi.org/10.1021/j100785a001 (bibliographic record; as tabulated in Wikipedia, Van der Waals radius, read 2026-10-25)",
    "PubChem CID 5234 (sodium chloride): density 2.17 at 25 °C/4 °C, relative to water at 4 °C (CRC Handbook of Chemistry and Physics, 94th edition, via the Hazardous Substances Data Bank), formula weight 58.44 g/mol (computed by PubChem), rock-salt cell edges 5.6035, 5.6393 and 5.6635 Å from Crystallography Open Database records 2108652, 4300180 and 4320809 (CC0); retrieved 2026-10-25",
    "water density 997.05 kg/m3 at 25 °C and 999.97 kg/m3 at 4 °C, IAPWS R6-95(2018), https://iapws.org/technical-guidance/release/IAPWS-95 (shared water-properties.csv); molecular weight 18.015 g/mol, PubChem CID 962 (computed by PubChem); retrieved 2026-10-25",
    "CODATA 2022, Avogadro constant 6.02214076e23 per mole (exact), https://physics.nist.gov/cgi-bin/cuu/Value?na (retrieved 2026-10-25)",
    "volumes and widths computed 2026-10-25 for this page"
  ]
}