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 ...

Lithium metal, a soft solid, that can be cut with a knife, is far too reactive to be found in its natural (metallic) form. This is because it belongs to the Group 1 element (alkali metals) on the ...

ONE of the first inklings that chemistry has an underlying pattern was the discovery, early in the 19th century, of lithium, sodium and potassium—known collectively as the alkali metals. Though ...