Interactive periodic table
All 118 elements with their properties (mass, electronegativity, radius, ionization energy, melting and boiling points…) from PubChem. Click a cell to open its card, compare up to four elements, revise with the quiz and print a blank table.
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Revise
Pick a question type, then start the quiz. Scores stay on this device.
Print a table
In the print dialog, choose “Save as PDF” to get a PDF. Cells outside the chosen range stay empty.
How to read the periodic table
Elements are ordered by increasing atomic number, the number of protons in the nucleus. Each row is a period: it corresponds to filling a new electron shell. Each column is a group (numbered 1 to 18): elements in the same group have the same number of valence electrons and similar chemistry, like the alkali metals (group 1), the halogens (group 17) or the noble gases (group 18).
The lanthanides (57 to 71) and actinides (89 to 103) belong to periods 6 and 7; they are shown on two separate rows so the table fits in width. They have no group number.
Where does the data come from?
All properties come from the PubChem periodic table (National Center for Biotechnology Information, USA), retrieved on 30 October 2026. When PubChem gives no value, the card says so: no data is estimated or filled in from another source. Each card links to the element's PubChem page.
Corrections made to the PubChem data:
Frequently asked questions
Why are some masses in brackets?
Technetium, promethium and the elements from polonium onwards (except thorium, protactinium and uranium) have no stable isotope and no fixed natural isotopic composition, so they have no standard atomic weight. The mass of their most stable isotope is given, and the table shows its mass number in brackets, e.g. [209] for polonium.
Why is lithium's mass 7.0 rather than 6.94?
For about ten elements (H, Li, B, C, N, O, Mg, Si, S, Cl, Ar, Br, Tl, Pb), the isotopic composition varies between samples. The Commission on Isotopic Abundances and Atomic Weights (CIAAW) gives an interval, e.g. [6.938, 6.997] for lithium, plus a conventional value (6.94) used in textbooks. PubChem rounds according to the uncertainty, hence 7.0. For an exercise, use the value given in the question.
Why is there no electronegativity for helium, neon or argon?
These noble gases form no known chemical bonds, so Pauling electronegativity, which is computed from bond energies, is not defined for them.
What does “predicted” mean for the state?
Superheavy elements only exist a few atoms at a time, for fractions of a second: their state at room temperature is a theoretical prediction, not a measurement.
Are my quiz answers sent anywhere?
No. The tool runs entirely in your browser; scores are stored on this device only.
How the table is organised
- Rows (periods): all elements in a row have the same number of occupied electron shells. A new row starts when a shell fills up.
- Columns (groups): elements in a column have the same number of valence electrons, hence similar chemistry. Sodium and potassium (group 1) both react violently with water.
- s, p, d, f blocks: they show the subshell being filled. Lanthanides and actinides (f-block) sit below the table so it fits on a page.
Trends to know
- Electronegativity rises to the right and upwards. Fluorine is the most electronegative (3.98 on the Pauling scale), caesium and francium the least.
- Atomic radius shrinks to the right (stronger pull from the nucleus) and grows downwards (extra shells).
- Ionisation energy peaks with the noble gases at the top right and is lowest for the alkali metals.
Choose “colour by” electronegativity, radius or ionisation energy: the gradient makes these trends, and their exceptions, visible at a glance.
Revising effectively
- Start with the first 20 elements in “name → symbol” mode, 10 questions a day.
- Move on to families (alkali metals, alkaline earth metals, halogens, noble gases) with “element → family”.
- Finish with “element → position”: knowing where an element sits lets you infer its properties.
- Keep “review my mistakes first” on: missed elements come back more often.
A classic mnemonic for the first nine elements (H, He, Li, Be, B, C, N, O, F): “Happy Henry Likes Beer But Could Not Obtain Food”.
For teachers
- Print a blank table, or one to complete with symbols, names or numbers, limited to elements 1–20 or 1–36, in A4 portrait or landscape, with its answer key.
- The comparison panel puts up to four elements side by side: ideal for comparing chlorine, bromine and iodine in a lesson on halogens.
- Data come from PubChem (NIH); element cards show the values used.
To draw lab set-ups, see the lab glassware diagrams.
Guide written and checked by Erwan Hautot · updated 30 October 2026.