Periodic Table of Elements
All 118 elements — hover or tap any element to see details. Click "View full details" to explore properties, uses, and safety data.
About the Periodic Table
The periodic table of elements organises all 118 known chemical elements by increasing atomic number. Elements are arranged in periods (rows) and groups (columns) so that elements with similar chemical properties fall in the same group. It was developed by Dmitri Mendeleev in 1869 and remains the cornerstone of chemistry.
Element Categories
Elements are classified into categories based on their physical and chemical properties: metals (alkali, alkaline earth, transition, post-transition), metalloids, non-metals (including halogens and noble gases), lanthanides, and actinides. These categories reflect trends in reactivity, conductivity, and bonding behaviour.
Periodic Trends
Moving across a period (left to right), atomic radius decreases, ionisation energy increases, and electronegativity increases. Moving down a group, atomic radius increases and ionisation energy decreases. These trends arise from the changing number of protons and electron shells.
How to Use This Table
Hover over or tap any element to see its atomic number, symbol, atomic mass, and category. Click "View full details" to open a full page with properties, industrial uses, safety information, and more from our chemical glossary database.