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 ...

Everything we can see and touch, and quite a lot that we can’t as well, is made of tiny particles called atoms. Some substances, like particles of this iron, contain only one kind of atom.

Everything in the world is made from about 100 different chemical elements that join together in different ways to form all the solids, liquids and gases we see around us. All of the elements have ...