Licences and credits · Bright Atoms

The short version

The words, lessons, simulations, drawings and software are ours. Share links freely, use the site in class and quote short extracts with credit. Ask before reusing more.
Every picture on the site is drawn in code by us. There are no photographs from anyone else.
The numbers come from IUPAC, NIST and PubChem, and each lesson names its own sources. Facts aren’t owned by anyone, but we credit the people who measured and published them.
The fonts are Instrument Sans and Fragment Mono, both under the SIL Open Font Licence.
Bright Atoms is not connected to IUPAC, NIST, PubChem, the Royal Society of Chemistry or any exam board.
If you think we have used something we shouldn’t, or got a credit wrong, tell us and we will put it right quickly.

1. What is ours

the text of the lessons, element pages, glossary and every other page;
the design of the site, and the Bright Atoms name and mark;
the simulations, diagrams and drawings, all of which are made in code;
the software that runs the site;
the way the data has been selected, checked, arranged and put together.

You may share a link to any page, show pages to a class, quote short extracts with credit to Bright Atoms and a link to the page, and print or save a page for your own or classroom use. Anything more, such as putting our text, simulations or software on another site, in a book, in a resource you sell or in a product, needs our written permission. Email hello@fallinghippo.com and say what you would like to do. We are glad to say yes to schools, teachers, libraries and non-profit projects, and we usually do.

2. Pictures

There are no photographs or borrowed images on the site. Every picture, from the orbital clouds to the emission lines and the periodic table, is drawn by our own code from the data described below. The colours of flames and spectral lines are our approximations of how they look, not measurements of colour.

3. Where the data comes from

What	Where from	Terms
Standard atomic weights of the elements	IUPAC Commission on Isotopic Abundances and Atomic Weights (CIAAW), abridged standard atomic weights, 2024	Published by IUPAC for scientific use, cited as CIAAW asks. The values are facts and we credit their source on every element page.
Ground-state electron configurations and first ionisation energies	NIST Atomic Spectra Database, ionization energies (NIST Standard Reference Database 78)	NIST data. NIST may hold rights in its Standard Reference Databases under the US Standard Reference Data Act. We use individual values, cite NIST on every page that uses them and don’t republish the database.
Wavelengths of emission lines	NIST Atomic Spectra Database, lines	As above.
Families, states at room temperature and electronegativities, and a second check on configurations	PubChem periodic table, US National Library of Medicine	PubChem’s own data is in the public domain. PubChem compiles some values from other sources, which keep their own terms.
Physical constants, such as the Avogadro constant	The SI, as defined by the BIPM in 2019, and CODATA recommended values	Published definitions and values.
Definitions of chemical terms	The IUPAC Gold Book	Cited by entry. We write our own definitions in plain English and link to the Gold Book’s.
Other values in the lessons	Named under each lesson	Each lesson lists its sources and the date it was checked.

Facts, figures and measurements aren’t covered by copyright in themselves, but collections of them can be, and many authors ask to be cited. We cite every source we use on the page that uses it, and the full list is on the sources page.

4. Fonts

The site uses two typefaces, both free under the SIL Open Font Licence 1.1 and served from this site, not from Google or anyone else, through the Fontsource packages:

Instrument Sans, © 2022 The Instrument Sans Project Authors, for headings and text;
Fragment Mono, © 2022 The Fragment-Mono Project Authors, for figures, labels and equations.

Each font’s copyright notice is on its Fontsource page and in the font files.

5. Software

The site is built with open-source software, used under its licences:

Software	Used for	Licence
Astro	Building the site	MIT
Fontsource	Delivering the fonts	MIT for the packages; the fonts themselves are under the SIL Open Font Licence

The simulations are written by us and use no outside libraries. The MIT licence requires us to keep the copyright notices of its authors with their code. They are in the packages and on the projects’ own pages.

6. Names and trade marks

IUPAC, NIST, PubChem, CIAAW, AQA, Edexcel, OCR, WJEC, CLEAPSS and other names on the site belong to their owners. We use them only to say where something comes from, or which part of a specification a lesson covers. A mention is not an endorsement either way. Bright Atoms is independent. It isn’t run, approved or sponsored by any of them.

7. How to ask us, or to tell us about a problem

To ask for permission to reuse our work, email hello@fallinghippo.com. Tell us what you want to use, where and why.

To tell us we have used something we shouldn’t, or got a credit wrong, email hello@fallinghippo.com with “Credit or copyright” in the subject. Please tell us:

who you are and, if you are writing for the owner, how you are connected to them;
which page and which text or data you mean, with the address;
what the problem is, and what you would like us to do;
how we can reach you.

We look at every message promptly, normally within 5 working days. Where something is wrongly credited we correct it, and where we’ve no right to use something we remove it while we sort it out.

8. Changes

We update this page when we add a new source or tool, and change the date at the top.

11 November 2026. First version.