may 2, 1869 - Dmitri Mendeleev: Mendeleev, a polymath created the modern structure of the periodic table. The elements were arranged in order of atomic weight and into various groups based on their compositions. One creative idea that is unique in Mendeleev's contribution to the periodic table was how he left gaps for future elements such as gallium and was able to predict their properties.
Added to timeline:
Date:
may 2, 1869
Now
~ 156 years ago