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 ... development and ...

His principal contribution to chemistry ... Periodic Tables between 1864-1870. His first table contained just 28 elements, organised by their valency (how many other atoms they can combine with).

These superheavy elements are the purview of a small group stretching the boundaries of chemistry. Can they extend the periodic table beyond the 118 in it now? Find out scientists are using particle ...