14 Sept 1869 Jahr - Dmitri Mendeleev - Classification of Elements (1869)

Beschreibung:

Mendeleev classified elements into 7 groups according to their atomic mass and found a correlation between atomic mass and the properties of an element. He arranged elements into a diagram called the Periodic Table. The table created by Mendeleev also alotted spaces for elements that hadn't been discovered yet and were found later in history.