jan 1, 1869 - Dimitri Mendeleev
Description:
He is considered the father of the periodic table. 60 elements were discovered by his time. Mendeleev had written the properties of elements on pieces of card. After organising the cards while playing patience he suddenly realised that by arranging the element cards in order of increasing atomic weight that certain types of element regularly occurred.Added to timeline:
Date:
jan 1, 1869
Now
~ 156 years ago