Interactive Periodic Table
Find any of the 118 recognised elements, narrow the table by position or category, inspect source-labelled atomic weights, and practise names, symbols and atomic numbers.
On a small screen, swipe the table horizontally to reach later groups.
Data provenance
What each value means
Sources checked 26 July 2026.
The table contains the 118 element names, symbols, atomic numbers and conventional group/period placement. Abridged standard atomic weights come from the CIAAW 2024 table. CIAAW does not assign a standard atomic weight to every radioactive element, so those entries say No standard atomic weight instead of presenting one isotope mass number as though it were a standard weight.
- Atomic weight is not the same as atomic number or mass number.
- Displayed weights are abridged values for general reference; the full CIAAW table includes uncertainties and, for some elements, intervals.
- State labels describe the commonly accepted state near 25 °C. The state of elements 104–118 is labelled not established.
- This tool does not predict reactions, bonding, electron configurations, laboratory safety or examination questions.
How to use the table
Search by element name, symbol or atomic number. Combine category, period and group filters to compare related elements. Select an element for its source-labelled summary, then copy, download or print those notes. Quiz mode practises only names, symbols and atomic numbers from the same validated 118-element dataset.
Why do some elements have no standard atomic weight?
Standard atomic weights apply to normal terrestrial materials with characteristic isotopic abundances. For elements without such an abundance, CIAAW leaves the standard atomic-weight field blank. An isotope mass number may appear in some periodic tables, but it is a different quantity.
Can I use these values in assessed or laboratory work?
Use this page for lookup and revision, then check the table or data sheet required by your institution. Laboratory work may require the full CIAAW value, uncertainty, interval or a specific isotope.