150 Anniversary of the Periodic Table of the Elements
The Periodic Table of the Elements is a value tool for chemists that should not be forgotten by young chemists. It is probably the most important single document in chemistry. It is the classification of the materials with which chemists work. Elements are included based on properties from atomic numbers, electron configurations, and chemical properties. Elements are presented in order of increasing atomic number.
Photo of Russian Scientist Dmitri Mendeleev
In 1869 Russian chemist Dimitri Mendeleev created the periodic table of the elements to keep atomic mass of different elements. He recognized that there would be other elements discovered so he left space for new ones. The Table started with 56 known elements in 1863.
In 2019 there are 118 confirmed elements. The first element is hydrogen the newest oganesson. Discoveries, are officially confirmed by the International Union of Pure and Applied Chemistry (IUPAC). For sure there will be new elements discovered, although it is becoming difficult to identify them or to make new ones.
