About Periodic Table Lab
Periodic Table Lab is a free web tool for comparing the properties of all 118 elements on one screen and reading the story of each one. It runs in your browser with no installation or sign-up, and nothing you type leaves your device.
Features
Interactive table of 118 elements
Standard layout with the lanthanides and actinides set apart. Hover over an element for a summary in the open space of the table; select it to open a detailed panel below.
Eleven property views
Compare category, state, atomic weight, electronegativity, atomic radius, ionization energy, density, melting point, boiling point, discovery year and block by shade.
Temperature and year sliders
Sweep from 0 K to 6,000 K to see solids melt and boil, or move through history to see the order in which elements were discovered.
Electron configuration and orbital boxes
Condensed and full notation, electrons per shell and an orbital diagram filled by Hund's rule.
Molar mass calculator
Molar mass, mass percentages and mass↔mole conversion for formulas with parentheses, brackets and hydrates.
A page for every element
Discovery history, name origin, main uses, isotopes and everyday examples, written for each element.
How to use
- Select an element in the table to open its properties and electron configuration below. Arrow keys move to neighbouring elements.
- Type a name, symbol or atomic number in the search box to highlight matches. Press Enter to select the first result.
- Choose a property under View; higher values are drawn in darker shades. The legend shows the value range of each step.
- Choose State (temperature) to reveal the temperature slider, then drag it to see where each element melts or boils.
- Enter a formula in the molar mass calculator for an instant result. Separate hydrates with a middle dot (·), a period or an asterisk.
Data and standards
Physical and chemical properties come from the PubChem Periodic Table published by the US National Library of Medicine (NIH/NLM). Atomic weights follow the 2024 abridged standard atomic weights of IUPAC's Commission on Isotopic Abundances and Atomic Weights (CIAAW). Melting and boiling points are given in kelvin; the states and electron configurations of superheavy elements are theoretical predictions. Discovery years are based on PubChem, with a few values (fluorine, aluminium, silicon, calcium, ruthenium, bohrium) corrected to the commonly cited year.
Frequently asked questions
Which atomic weights are used?
The 2024 abridged standard atomic weights from CIAAW (IUPAC's Commission on Isotopic Abundances and Atomic Weights). Elements with no stable isotope show the mass number of a representative isotope in brackets, for example technetium [97].
Why are the lanthanides and actinides shown separately?
Periods 6 and 7 each contain 15 elements that fill f orbitals. Placing them inline would make the table 32 columns wide, so by convention they are pulled out into two rows below.
How reliable are the data for superheavy elements?
Elements beyond 104 have only been made a few atoms at a time, so their melting points, densities and states have never been measured. Values shown are theoretical predictions and are labelled as predicted.
Why is aluminium spelled that way?
Element names follow the IUPAC recommended spelling (aluminium, caesium, sulfur). Searching for aluminum or cesium also works.
Is my formula stored on a server?
No. Every calculation runs inside your browser and nothing you type is sent anywhere.
I found an error.
Please email the atomic number and the issue from the contact page. We will check the source and correct it.