The Periodic Table of Elements is an organized list of all known chemical elements, arranged in order of their atomic number. It was first developed by Russian chemist Dmitri Mendeleev in 1869 and has since been used as a standard reference for the properties of chemical elements. Each element is listed with its atomic number, symbol, name, and atomic mass. The table also includes information about the element's physical and chemical properties, such as boiling point, melting point, and electronegativity.