Properties and Reactions — Key Discoveries

Key Discoveries

Mendeleev's Periodic Law and the Prediction of Elements

1869

Dmitri Mendeleev's formulation of the periodic law, which stated that the properties of elements are a periodic function of their atomic weights, was a monumental leap in chemical…

Discovery of Electron and Atomic Structure (J.J. Thomson, Rutherford, Bohr)

Late 19th - Early 20th Century

The sequential discoveries of the electron by J.J. Thomson, the nuclear atom by Ernest Rutherford, and the quantized electron shells by Niels Bohr fundamentally transformed our…