August 20, 1779 – Birth of Jöns Jacob Berzelius, considered one of the fathers of modern chemistry

He was a Swedish doctor, chemist, and pharmacist who among great contributions included:

• Law of definite proportions. Table of relative atomic weights, where the atomic weight of oxygen was fixed at 100. This work provided evidence in favor of Dalton's atomic theory: that inorganic chemical compounds are composed of atoms combined in whole quantities.

By discovering that atomic weights are not integer multiples of the weight of hydrogen, Berzelius also disproved Joseph Louis Proust's hypothesis that elements are built from hydrogen atoms.

• Chemical nomenclature. To systematize his experiments, he developed a system of chemical notation in which elements were denoted by simple symbols. This is the same system used today in the molecular formula, the only difference being that instead of the subscripts used today (for example, H2O), Berzelius used superscripts (H2O).
• Discovery of new chemical elements. He discovered thorium, cerium, and selenium, and was the first to isolate silicon, zirconium, and titanium. In addition, the students who worked with him in the laboratory also discovered lithium and rediscovered vanadium.
• He coined new chemical terms. As are catalysis, polymer, isomer, isomerism, halogen, organic radical, and allotrope, although their original definitions differed drastically from their modern usage.
• Great contribution to biology. He was the first to make the distinction between organic compounds (those that contain carbon), and inorganic compounds, and he coined the term "protein."

If you want to know more about this scientist who has made great contributions to science, click on the following link: Jöns Jacob Berzelius