1905, Atoms Proved to Exist

Photo Credit: www.biography.com
Year: 1905
Chemist: Albert Einstein
Contribution: Proved Atoms Exist

Albert Einstein is famous for many reasons, but he too contributed to the progression of the atomic model by coming up with concrete proof atoms in fact exist. In 1905 Einstein wrote a paper that mathematically proved the existence of atoms, relying heavily on Brownian motion. Brownian motion consists of the way particles move through gas and liquid, and in 1909 Jean Perrin proved Einstein's calculations to be correct.

Atomic theory would be worth very little if it turned out atoms did not exist after all, but the hard evidence ensured that atoms and their many parts would retain significance long into the future. This is, of course, an incredible relief. 

Information Credits: ANS Nuclear Cafe, Tesla Memorial Society of New York