Interactive Periodic Table

Yes. Every feature, the quiz and the PDF, PNG and CSV downloads are free, with no account and no watermark.

Atomic weights are the IUPAC (CIAAW) 2024 standard atomic weights. Ionization energies and electron configurations come from the NIST Atomic Spectra Database, isotope abundances from NIST, heat capacities from the NIST-JANAF tables, and most other properties from PubChem. Values were cross-checked against other public references.

For some elements, such as hydrogen and carbon, the atomic weight varies with the source of the sample, so IUPAC gives an interval; the table shows a conventional value. Radioactive elements without a standard atomic weight show the mass number of their longest-lived isotope in square brackets.

Slide the temperature from 0 to 6000 K. Each element is shown as solid, liquid or gas by comparing the temperature with its melting and boiling points at normal atmospheric pressure. Helium never freezes at that pressure, and carbon and arsenic turn straight into gas.

Only bromine and mercury are liquid at 25 °C. Gallium and caesium melt just above it, at about 30 °C and 28.5 °C, so they turn liquid on a warm day.

Yes. Use Print for a clean one-page table, or download a high-resolution PDF or PNG poster in A4 or A3. The CSV file has every value for spreadsheets.

Yes. The table scrolls and zooms with two fingers, the List view shows the elements as a sortable table, and the quiz has large buttons.

Superheavy elements exist only a few atoms at a time, so properties such as density or melting point have never been measured. The table marks missing values instead of guessing.