About Periodic Table

What this site is

Periodic Table (periodictable.page) is a free, interactive periodic table of the chemical elements. It is for students revising for an exam, teachers who want a clear table to project in class, and anyone who wants to look up an element's atomic number, atomic mass, electron configuration or melting point without wading through a textbook.

What you'll find here

• The interactive periodic table: all 118 elements in the classic 18-column or wide 32-column layout. Recolour it by family, by any of 24 properties, by state at a chosen temperature, by electron block, by isotope count or by oxidation state, and click any tile for its element card.
• Element pages: one for each of the 118 elements, with a full property list, the electron configuration and shell diagram, a 3D Bohr model where one exists, and links to its neighbours.
• Element family pages: one for each of the ten families, from the alkali metals to the actinides, with a sortable comparison table and trend charts.
• Search and sitemap: find an element by name, symbol or atomic number with the search box at the top of every page, or browse everything on the sitemap.

Where the data comes from

Atomic weights, melting and boiling points, densities, ionisation energies and the other values come from the standard reference data published by IUPAC and NIST, as collected in open-source element datasets, including the mendeleev Python package. Atomic masses of elements with no stable isotope are shown in brackets, as the mass number of the longest-lived isotope.

• The Compounds tab on the periodic table shows example compounds taken from PubChem, the open chemistry database of the US National Library of Medicine, and saved with the site.
• The element cards on the periodic table link to each element's Wikipedia article for further reading.

Densities are always given in g/cm³, including for gases, so that every element can be compared on one scale.

Who runs Periodic Table

Periodic Table is built and maintained by Unnikrishnan P, an independent developer and designer based in India who makes free, privacy-friendly browser tools.

• What he does here: builds the interactive table and every element and family page, writes the guides, and checks the values against the reference data before a page goes live.
• Skills: front-end development, interface and graphic design, data visualisation, motion design and video editing.
• Background: a banking and finance graduate (B.Com, Christ University, Bengaluru), which is where the care over numbers, units and worked calculations comes from.

Read his full profile or find him on LinkedIn.

How accuracy is checked

Every element value is taken from the reference data rather than typed by hand, and the derived figures (Celsius conversions, family averages, trend charts) are calculated from it when the site is built. Worked examples in the guides, such as molar mass calculations, are checked step by step. If you spot a value that looks wrong, please tell us through the contact page and include your source.

Your privacy

There are no accounts or sign-up forms. The table, search and element pages work in your browser.

Like most sites, we use analytics and advertising services that collect limited usage data such as pages visited. The privacy policy explains exactly what is collected and how to opt out.

How the site is funded

Periodic Table is free to use. It is supported by advertising shown through Google AdSense, which is kept separate from the content and never changes any element data. Advertising and analytics are explained in the privacy policy and the terms of use.

Get in touch

Found a mistake, or want a feature added to the table? Use the contact page.