All resembled known elements so closely that they could not be separated by chemical analysis ... recognized by Sir William Ramsay and O. Hahn only because it is formed from thorium through ...

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 ...

A chemical element is one of those squares on the periodic table that adorns many a classroom wall. Sure. But what is an element really? It is a more subtle question that you might realise.

The first 94 chemical elements ... Water is made from the element hydrogen bonded to the element oxygen. Water molecules are made up of two elements - hydrogen (white atoms) and oxygen (red ...

On 17 February 1869, Russian chemist Dmitri Mendeleev jotted down the symbols for the chemical elements, putting them in order according to their atomic weights and inventing the periodic table.