Terms of Use
The rules for using chem.5l5l.net, the status of the data, and the limits of what this site can promise.
Last updated: November 1, 2026
Acceptance of these terms
By accessing chem.5l5l.net you agree to these Terms of Use. If you do not agree with them, please do not use the site.
Nature of the service
The site provides educational and informational reference data about chemical elements. It is not professional advice of any kind, and it must not be used as the sole basis for laboratory work, safety decisions, regulatory submissions, medical or forensic conclusions, or any other consequential decision.
Accuracy of the data
We work to keep the published values accurate and to cite their source, but we make no warranty that the site is error-free, complete, or fit for a particular purpose. Element properties such as atomic mass, electronegativity and ionization energy are measured under specific conditions and may legitimately differ between references.
Always verify safety-critical or regulatory-critical values against the primary literature, your institution's protocols and qualified professionals.
Intellectual property
The site design, code, layout and original text are owned by the operator of chem.5l5l.net and may not be reproduced commercially without permission.
The underlying element data is derived from PubChem (U.S. National Library of Medicine) and is in the public domain. Element name labels come from Wikidata and are contributed under the Creative Commons CC0 license. Attribution to PubChem and Wikidata is appreciated where you reuse the data.
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Limitation of liability
To the maximum extent permitted by law, the operator of this site is not liable for any loss or damage arising from use of, or reliance on, the information published here, including laboratory or safety outcomes of any kind.
Changes to these terms
We may revise these Terms at any time. The revision date appears at the top of this page, and continued use of the site after a revision means you accept the updated Terms.
Contact
Questions about these Terms can be sent to the address below.