The periodic table, also called the periodic table of elements, is an organized arrangement of the 118 known chemical elements. The chemical elements are arranged from left to right and top to bottom ...

When Dimitri Mendeleev published the first periodic table 150 years ago, only about half as many elements were known as today. Over the ensuing decades, researchers have added new names to the chart, ...

The periodic table of chemical elements, often called the periodic table, organizes all discovered chemical elements in rows (called periods) and columns (called groups) according to increasing atomic ...