NIST Atomic Weights and Isotopic Compositions with Relative Atomic Masses

The atomic weights are available for elements 1 through 118 and isotopic compositions or abundances are given when appropriate. Version 3.0.

Data and Resources

Field Value
accessLevel public
accrualPeriodicity irregular
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language {en}
license https://www.nist.gov/open/license
modified 2010-07-01 00:00:00
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publisher National Institute of Standards and Technology
resource-type Dataset
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  • GEO
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  • National
  • North America
  • United States
  • atomic-mass-evaluation
  • atomic-weights
  • commission-on-atomic-weights-and-isotopic-abundances
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  • subcommittee-for-isotopic-abundance
isopen False
license_id other-license-specified
license_title other-license-specified
maintainer Karen Olsen
maintainer_email karen.olsen@nist.gov
metadata_created 2025-09-23T21:05:26.193510
metadata_modified 2025-09-23T21:05:26.193517
notes The atomic weights are available for elements 1 through 118 and isotopic compositions or abundances are given when appropriate. Version 3.0.
num_resources 1
num_tags 22
title NIST Atomic Weights and Isotopic Compositions with Relative Atomic Masses