\(\renewcommand\AA{\text{Å}}\)
Mass¶
periodictable.mass
¶
Adds average mass for the elements:
- mass, mass_units (u)
The molar mass averaged over natural isotope abundance.
Adds mass and abundance information for isotopes:
- mass, mass_units (u)
The molar mass of the individual isotope.
- abundance, abundance_units (%)
Natural abundance for the isotope.
Atomic Weights and Isotopic Composition [1].
The atomic weights are available for elements 1 through 112, 114, & 116 and isotopic compositions or abundances are given when appropriate. The atomic weights data were published by Coplen [2] in Atomic Weights of the Elements 1999, (and include changes reported from the 2001 review in Chem. Int., 23, 179 (2001)) and the isotopic compositions data were published by Rosman [3] and Taylor [4] in Isotopic Compositions of the Elements 1997. The relative atomic masses of the isotopes data were published by Audi [5] and Wapstra [6] in the 1995 Update To The Atomic Mass Evaluation.
This data has been compiled from the above sources for the user’s convenience and does not represent a critical evaluation by the NIST Physics Laboratory. http://physics.nist.gov/PhysRefData/Compositions/
Neutron mass from NIST Reference on Constants, Units, and Uncertainty http://physics.nist.gov/cuu/index.html
- periodictable.mass.abundance(isotope)¶
Natural abundance.
- Parameters:
isotope : Isotope
- Returns:
abundance : float | %
- Reference:
Coursey. J. S., Schwab. D. J, and Dragoset. R. A., NIST Atomic Weights and Isotopic Composition Database.
- periodictable.mass.init(table, reload=False)¶
Add mass attribute to period table elements and isotopes
- periodictable.mass.mass(isotope)¶
Atomic weight.
- Parameters:
isotope : Isotope
- Returns:
- massfloat | u
Atomic weight of the element.
- Reference:
Coursey. J. S., Schwab. D. J, and Dragoset. R. A., NIST Atomic Weights and Isotopic Composition Database.