Explore all 118 elements with an interactive periodic table. Click any element to see detailed information including atomic mass, electron configuration, and discovery year.
The periodic table is a tabular arrangement of chemical elements organized by atomic number, electron configuration, and recurring chemical properties. First devised by Dmitri Mendeleev in 1869, it currently contains 118 confirmed elements arranged in 18 groups and 7 periods.
1. Click any element cell to view detailed information including atomic number, mass, electron configuration, discovery year, and a fun fact.
2. Click a category button in the legend to highlight all elements of that type. Click again to deselect.
3. Type in the search box to find elements by name (English/Korean), symbol, or atomic number.
Periods (horizontal rows) contain elements with the same number of electron shells. Groups (vertical columns) contain elements with the same number of valence electrons, giving them similar chemical properties.
Element symbols often come from Latin names. For example, Fe (Iron) from 'Ferrum', Au (Gold) from 'Aurum', Pb (Lead) from 'Plumbum'. Modern elements use the first 1-2 letters of their English names.
Lanthanides (57-71) and actinides (89-103) belong to periods 6 and 7 group 3, but are placed separately to keep the table compact. They are known as f-block elements.
All elements from technetium (43) onward have radioactive isotopes. Naturally radioactive elements include uranium (92), radon (86), radium (88), and polonium (84). All transuranic elements (93+) are synthetically produced.
The periodic table is the cornerstone of modern chemistry. In 1869, Dmitri Mendeleev arranged elements by atomic weight and discovered periodic patterns, predicting the existence and properties of undiscovered elements. Today's table is organized by atomic number (proton count), spanning 18 groups and 7 periods.
Elements are broadly classified as metals, metalloids, and nonmetals. Metals include alkali metals, alkaline earth metals, transition metals, post-transition metals, lanthanides, and actinides. Nonmetals include halogens and noble gases. Elements in the same category share similar electron configurations and chemical reactivity.
Periodic table elements permeate daily life. Iron (Fe) and aluminum (Al) underpin construction and transportation. Silicon (Si) is the backbone of computers and smartphones. Oxygen (O), carbon (C), hydrogen (H), and nitrogen (N) are essential for life. Rare earth elements are critical for modern electronics and renewable energy technologies.