Year: 2025
Type: article
Abstract: The data given in this table are from the CODATA recommended values of 2018 and published in 2021 [17], they are also available online (see https://pml.nist.gov/cuu/Constants/,accessed March 6, 2022).The revision of the SI became effective on May 20, 2019 and a subset of the relevant fundamental constants was published in 2018 [18], also listed in the SI Brochure [3].The standard uncertainty in the least significant digits is given in parentheses.(1) This constant is defined in the SI as of May 20, 2019 [3,17] (and refs.therein).(2) For the defined irrational number, only a finite number of digits are given here (indicated by ...).(3) u is the symbol of the (unified) atomic mass unit, for which the symbol Da (dalton) can be used as well.(4) The molar mass of unbound carbon-12 is given by 11.999 999 995 8(36)×10 -3 kg mol -1 .m a ( 12 C) = 12 u = 12 Da, therefore, M ( 12 C) = 12 M u ≈ 12×10 -3 kg mol -1 .(5) Since the values of the elementary charge e, the Avogadro constant N A , the Boltzmann constant k, the Planck constant h, and the speed of light in vacuum c 0 are defined fundamental constants, consequently the Faraday constant, the molar gas constant, the Stefan-Boltzmann constant, the first and second radiation constants, as well as the von Klitzing and Josephson constants have no uncertainty.(6) When expressed in SI units, the numerical value of this constant can be calculated exactly, but only a finite number of digits are given here (indicated by ...).
Source: ChemViews
Language: English
Subfield: History and Philosophy of Science
Field: Arts and Humanities
Domain: Social Sciences
Open Access status: bronze
OpenAlex ID: W4409339744