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Terms of use
The terms you agree to by using this site, and what the element data is and is not suitable for.
Last updated 6 August 2026
These terms cover your use of Periodic Table. They are short because the site is simple: it is a free reference tool, nobody signs up for anything, and nobody pays for anything. Using the site means you accept what follows.
What you may do
Read it, search it, use it in class, put it on a projector, keep it open during homework, print a page, or link to any page from anywhere. Teachers are welcome to point a whole class at it. None of that needs permission and none of it costs anything.
You may quote figures from the site in your own work. If you are reproducing a substantial amount of the element data, please credit the underlying source described on the about page, which is published under a Creative Commons licence that requires attribution.
What you may not do
- Scrape the site at a rate that degrades it for other people, or republish it wholesale as your own site.
- Interfere with the site, probe it for weaknesses, or try to get at parts of the server that are not published pages.
- Remove, hide or interfere with the advertising that pays for the site being free.
- Use the site in a way that breaks the law where you are.
About the data
Every effort is made to keep the numbers right, and the sources are named openly so you can check them. Even so, chemistry data is unusually easy to get subtly wrong: published values differ between references, some properties have never been measured, and figures for the heaviest synthetic elements are predictions rather than observations.
Treat this site as a study and reference aid, not as a laboratory, medical, safety or engineering authority. Do not rely on it for anything where an incorrect value could hurt someone or cost money. For work like that, use a primary source such as the CRC Handbook or an IUPAC publication.
The site is provided as it is, with no warranty of any kind. To the extent the law allows, we are not liable for loss or damage arising from your use of it or from anything you did on the strength of a figure you read here.
Corrections
If you find a wrong value, tell us on the contact page. We would rather be corrected than confident, and corrections are made quickly.
Advertising
Advertising keeps this site free. We do not control which specific adverts appear and showing one is not an endorsement of the advertiser. Anything you buy from an advertiser is between you and them. How advertising cookies work is described in the privacy policy.
Links to other sites
Some pages link to outside sources so you can read further or verify a figure. We do not control those sites and are not responsible for what they publish.
Ownership
The design, written explanations, charts, games and code on this site belong to Periodic Room. The underlying element measurements come from the sources listed on the about page and stay under their own licences. Element names, symbols and physical constants are facts and belong to nobody.
Availability
The site is offered on a best effort basis. Pages may be changed, moved or taken down at any time, and no promise is made that it will always be reachable.
Changes to these terms
These terms may be updated. The date at the top changes when they do, and continuing to use the site after a change means you accept the new version.
Getting in touch
Anything to do with these terms can go to support@periodicroom.com.