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 ...

Copper has been used by humans for as much as 7000 years and elements such as gold, silver, tin, lead and mercury have ... The section in the middle of the table is called the Transition Metals.

Bismuth, the 83rd element in the periodic table, has been known since ancient times, but was often confused with lead and tin. In 1753, Claude François Geoffroy from France demonstrated that ...

This year marks the 150th anniversary of the publication of Mendeleev’s Periodic Table of Chemical Elements in 1869. In celebration, the United Nations Educational, Scientific, and Cultural ...