Interactive Periodic Table of Elements
What is the periodic table?
The periodic table of elements arranges all 118 known chemical elements by increasing atomic number into horizontal rows called periods and vertical columns called groups. First published by Dmitri Mendeleev in 1869, its power is that elements line up by recurring chemical behaviour: members of the same group have the same number of valence electrons, so they react in similar ways. Metals occupy the left and centre, non-metals the upper right, and the metalloids form the staircase between them.
How to read it
Each cell shows an element's atomic number (its proton count) and its one- or two-letter symbol. Moving left to right across a period, the atomic number rises by one at each step and a new electron is added to the same outer shell; moving down a group, each element adds a whole new shell. The two detached rows beneath the table are the lanthanides (57–71) and actinides (89–103), the f-block elements pulled out to keep the chart compact.
Periodic trends you can visualise
Use the Color by control (or the / key) to shade the whole table by any of 20 properties, from low (blue) to high (red), so the underlying periodic trends jump out:
- Atomic radius increases down a group (more shells) and decreases across a period (stronger nuclear pull).
- Electronegativity and ionization energy do the opposite — rising across a period and falling down a group.
- Atomic mass, density, melting and boiling points, specific heat and more each reveal their own pattern across the chart.
Element families
Families group elements that behave alike. Click any family below the table to highlight its members.
Electron blocks: s, p, d and f
An element's block tells you which electron sub-shell its outermost electrons occupy — a quick guide to its chemistry.
How to use this interactive periodic table
- Find an element — click any cell, or type a name, symbol or atomic number in the search box (it also matches families and blocks).
- Read its properties — the panel lists atomic mass, electron configuration, electronegativity, melting and boiling points, density and more, with an animated 3D atom model.
- Visualise a trend — switch the Color by mode (or press / and \) to recolour the table by any property.
- Compare elements — turn on Compare and pin up to four elements to see their Bohr diagrams and key numbers side by side.