01Interactive periodic table of 118 elements

Interactive periodic table — properties, compounds and trends for 118 elements

118 elements · 18 groups · 7 periods · curated NIST · IUPAC · CODATA · PubChem data

→Explore the tableCompounds library
Click a cell to open the page · arrow keys to navigate
1H2He3Li4Be5B6C7N8O9F10Ne11Na12Mg13Al14Si15P16S17Cl18Ar19K20Ca21Sc22Ti23V24Cr25Mn26Fe27Co28Ni29Cu30Zn31Ga32Ge33As34Se35Br36Kr37Rb38Sr39Y40Zr41Nb42Mo43Tc44Ru45Rh46Pd47Ag48Cd49In50Sn51Sb52Te53I54Xe55Cs56Ba72Hf73Ta74W75Re76Os77Ir78Pt79Au80Hg81Tl82Pb83Bi84Po85At86Rn87Fr88Ra104Rf105Db106Sg107Bh108Hs109Mt110Ds111Rg112Cn113Nh114Fl115Mc116Lv117Ts118Og
57La58Ce59Pr60Nd61Pm62Sm63Eu64Gd65Tb66Dy67Ho68Er69Tm70Yb71Lu
89Ac90Th91Pa92U93Np94Pu95Am96Cm97Bk98Cf99Es100Fm101Md102No103Lr
02What is this periodic table?

What is this periodic table?

The periodic table classifies all 118 known chemical elements by atomic number, electron configuration and recurring chemical properties. This interactive Mendeleev edition exposes every element's atomic, physical, thermal, electrical and nuclear data in a single keyboard-navigable grid. Heatmaps reveal periodic trends — electronegativity, atomic radius, ionisation energy, density, melting and boiling points — at a glance, while 3D Bohr atoms and ball-and-stick molecules sit one click away. Numbers come straight from NIST, IUPAC 2021, CODATA and PubChem with units in SI and zero rounding at the source.

  • 118 elements with curated atomic and physical data
  • Compounds library with 3D structures and PubChem links
  • Industrial processes — Haber-Bosch, fission, electrolysis
  • Speedrun, atomic battleship and 'Who Am I?' quizzes
03Browse by category

Browse by category

Drill into the table from any angle — chemical family, period, valence block, periodic trend or industrial application.

04Trusted scientific sources

Trusted scientific sources

Every value displayed here is sourced from peer-reviewed reference databases. No estimation, no rounding at the source.

NIST
Atomic Spectra Database, Chemistry WebBook and CODATA fundamental constants for ionisation energies, electron configurations and atomic data.
IUPAC 2021
Standard atomic weights, recognised element names and recommended group numbering, including the 2016 additions Nh, Mc, Ts and Og.
CODATA
2018 recommended values of fundamental physical constants — Avogadro, Planck, atomic mass unit — used in derived calculations.
PubChem
NCBI compound library: SMILES, InChI, CID identifiers and 3D coordinates for the molecules in the compounds library.
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05Frequently asked questions

Frequently asked questions

How many elements are on the periodic table?

There are 118 confirmed chemical elements, from hydrogen (Z = 1) to oganesson (Z = 118). Elements 113 to 118 (Nh, Fl, Mc, Lv, Ts, Og) were officially named by IUPAC in 2016 and complete the 7th period.

Where does the data come from?

All atomic, physical and nuclear values are taken from NIST (Atomic Spectra Database, Chemistry WebBook), IUPAC 2021 standard atomic weights, CODATA recommended constants and the PubChem compound library. Source URLs are listed on each element page.

Is the periodic table free to use for teaching?

Yes. Mendeleev is an open educational project: every page is free, the fullscreen view exports printable A3 PDFs and high-resolution PNGs, and a markdown copy of every page is available for offline use or LLM ingestion.

Why are some properties marked 'predicted'?

Transactinides (Z ≥ 104) are only synthesised as a few atoms with sub-second half-lives. Many of their physical properties are theoretical predictions, not experimental measurements. The element page flags these values explicitly.

How can I learn the periodic table by playing?

The Games section offers three educational modes: Speedrun (place announced elements as fast as possible), Atomic Battleship (locate hidden elements on the grid) and 'Who Am I?' (guess elements from progressive clues). Three difficulty levels and local high scores are saved in your browser.

Can I export the table for printing?

Yes. The Fullscreen view exports the periodic table as a high-resolution PNG (300 dpi) and as a printable A3 PDF, both at lossless quality and ready for classroom whiteboards or wall posters. Each individual element page also offers a markdown copy for offline use.