Interactive Periodic Table of Elements

A chart that arranges all known chemical elements by increasing atomic number so that elements with similar properties line up in columns.

By atomic number, in 7 horizontal periods and 18 vertical groups. Position reflects electron arrangement, which drives chemical behavior.

Groups are columns (1–18) whose elements often share valence-electron patterns. Periods are rows (1–7) and match the outermost electron shell. Blocks (s, p, d, f) name the subshell receiving the last electron.

Atomic number is the count of protons in the nucleus and defines the element. Atomic mass is the weighted average mass of an element's isotopes, in unified atomic mass units.

The distribution of an atom's electrons among orbitals, such as 1s² 2s² 2p² for carbon. A few elements have well-known exceptions to the simple filling order.

Metals usually conduct electricity and heat well and are often malleable. Nonmetals generally do not, and are often gases or brittle solids. Metalloids, such as silicon, have intermediate properties.

The elements of group 18. They have full outer shells and rarely react.

Two rows of f-block elements (atomic numbers 57–71 and 89–103) usually shown below the main table to keep it compact.

A table of all known chemical elements arranged by atomic number and recurring properties.

118 confirmed elements, from hydrogen (1) to oganesson (118).

The number of protons in an atom's nucleus; it identifies the element.

A one- or two-letter abbreviation, such as O for oxygen or Fe for iron.

Groups are the 18 vertical columns; periods are the 7 horizontal rows.

Group 18 elements (helium, neon, argon, krypton, xenon, radon, oganesson) that are generally unreactive.

How an atom's electrons are arranged in orbitals, e.g. 1s² 2s² 2p² for carbon.

Use the search box above the table, press “/”, or use Quick Element Lookup with a name, symbol, or atomic number.

Two f-block series (57–71 and 89–103) shown as separate rows below the main table.