Find an element
Type a name, symbol, number or family in the search box, or point at a square to see its details. Choose a square, or press Enter on it, to open its full page of facts.
Elemental Periodic TableInteractive Periodic Table of the Elements
All 118 elements with the source of every value: heat the table to see what melts and boils, rewind the history of discovery, chart trends, compare elements, work out molar masses, balance equations and test yourself, with nothing uploaded.
Periodic table
Heat it, rewind history or colour it by a property. Pick any element for its full story.
Trends
The table is periodic because properties repeat. Chart any property across the elements, plot two against each other, or follow the history of discovery.
Show the numbers
Compare
Put up to four elements side by side. Each bar shows where the value sits among all elements, so you can see more than which one is bigger.
Lab
Work out molar masses and empirical formulas, balance equations and turn molecules in 3D.
Symbols are case-sensitive: Co is cobalt, CO is carbon monoxide. Use brackets for groups and a dot for water of crystallisation.
Empirical formula from percentages
Enter the mass percent of each element from an analysis. Add the molar mass if you know it to get the molecular formula too.
Separate substances with + and the two sides with = or ->. Ions are fine: write charges with ^, like Fe^3+ or MnO4^-, and an electron as e^-.
Quiz
Ten questions a round, or the big one: name all 118 from memory. Press 1 to 4 to answer from the keyboard.
Everything is worked out in this browser; nothing is uploaded. Atomic weights: CIAAW 2024. Melting and boiling points, densities, electronegativity, electron affinity and crust abundance: CRC Handbook of Chemistry and Physics. Ionisation energies: NIST. Values never measured are shown as unknown. Press / to search the table while you use it.
How to Use the Periodic Table
Heat the table
Drag the temperature slider to see which elements are solid, liquid or gas, from absolute zero to the surface of the Sun. Switch between Celsius, kelvin and Fahrenheit.
Rewind history
Move the Known by slider, or press Replay history, to watch the elements appear in the order they were found, from the metals of antiquity to tennessine in 2010.
See the trends
Colour the table by a property, chart it across all elements on the Trends tab, or plot two properties against each other. Compare puts up to four elements side by side.
Work it out in the Lab
Get the molar mass of any formula, an empirical formula from percentages, a balanced equation for molecules or ions, and 23 molecules and crystals to turn in 3D.
Test yourself
Ten-question rounds on positions, names, symbols and families, or the challenge to name all 118 elements from memory against the clock.
Why Use This Periodic Table?
📚 Every value has a source
Atomic weights from IUPAC's atomic weights commission, physical data from the CRC Handbook, ionisation energies from NIST. Values that have never been measured are marked unknown, not guessed.
🌡️ States you can see
The squares fill and empty as you heat the table, so melting and boiling points become a picture: mercury and bromine are liquid at room temperature, gallium melts just above it.
⚖️ A real chemistry calculator
Molar mass with hydrates and brackets, empirical and molecular formulas from an analysis, and an equation balancer that handles ions and electrons with exact whole numbers.
🧪 Shapes in 3D
Water, ammonia, methane, sulfur hexafluoride, benzene, diamond, a salt crystal and buckminsterfullerene, with bond angles and lone pairs to turn and zoom.
🔒 Nothing uploaded
No account and no upload. The table, the charts and the calculators run in your browser, and your settings and best scores stay on this device.
📱 Works on a phone
The table fits the screen, a list view gives every element a full row, and each element's page has buttons to step to the next and previous element.
The Periodic Table Explained
🔢 How the table is ordered
Elements are ordered by atomic number, the number of protons in the nucleus. Rows are periods: each one adds a new electron shell. Columns are groups of elements with the same number of outer electrons, which is why they behave alike. The two rows below the table, the lanthanides and actinides, belong in periods 6 and 7 and are set apart to keep the table narrow.
📏 Where the numbers come from
Standard atomic weights: CIAAW, Standard Atomic Weights 2024 (abridged to five figures). Mass numbers in square brackets: CIAAW's list of the radioactive elements, from NUBASE2020. Melting and boiling points, densities, Pauling electronegativity, electron affinity and abundance in the crust: CRC Handbook of Chemistry and Physics (95th and 97th editions), taken from the open mendeleev data set. Ionisation energies: NIST Atomic Spectra Database. Covalent radii: Cordero and others (2008). Atomic radii: Rahm, Hoffmann and Ashcroft (2016 and 2017).
🕰️ Discovery years
A year of discovery can mean the first time an element was recognised or the first time it was isolated, so books give different years for some. This table follows PubChem's periodic table or Wikidata wherever either agrees, the Nobel Prize citation for fluorine (isolated by Henri Moissan in 1886) and the IUPAC and IUPAP working group's verdicts for elements 102, 105 and 107.
Frequently Asked Questions
Where do the numbers come from?
Atomic weights are the 2024 standard atomic weights of IUPAC's Commission on Isotopic Abundances and Atomic Weights (CIAAW), in their five-figure form. Melting and boiling points, densities, electronegativity, electron affinity and the amount in the Earth's crust come from the CRC Handbook of Chemistry and Physics, ionisation energies from the NIST Atomic Spectra Database, covalent radii from Cordero and others (2008) and atomic radii from Rahm, Hoffmann and Ashcroft (2016 and 2017). Where no measured value exists, the tool says unknown instead of guessing.
Why do some elements show a number in square brackets?
Radioactive elements such as technetium, radon and plutonium have no standard atomic weight, because their make-up depends on where the sample came from. As in IUPAC's own table, the tool shows the mass number of the longest-lived isotope in square brackets, taken from CIAAW's list, and uses it for molar masses.
How does the temperature slider work?
Each square fills to show the element's state at the temperature you choose, at normal atmospheric pressure: full for a solid, half for a liquid, empty with a dashed edge for a gas. Carbon and arsenic turn straight from solid to gas. Where a melting or boiling point has never been measured, the square shows that the state is unknown.
How do I balance a chemical equation here?
Open Lab, choose Balance and type the equation with + between substances and = or -> between the two sides, for example Fe + O2 = Fe2O3. The tool finds the smallest whole numbers that balance every element, and the charge when you write ions such as Fe^3+ or MnO4^-, and shows a table that checks each atom.
Can it work out molar mass?
Yes. Type a formula such as H2SO4, Ca(OH)2 or CuSO4.5H2O in Lab, Molar mass. Symbols are case-sensitive: Co is cobalt, CO is carbon monoxide. You get the molar mass in g/mol, the share of each element and a converter between grams, moles and the number of formula units.
Is the quiz suitable for students?
Yes. There are four kinds of ten-question rounds (find an element on a blank table, name it from its symbol, pick its symbol, pick its family) over the first 20, 54 or all 118 elements, and a challenge to name all 118 from memory. Your best scores stay on this device.
Is anything I type sent anywhere?
No. Everything is worked out in your browser. Your settings and quiz scores are kept only in this browser on this device. A shared link holds only an element, a list of elements or a formula, and it is made only when you press Copy link.