
August Wilhelm Hofmann was the first to introduce physical representations of molecules into lectures during his Friday Evening Discourses presentation "On the Combining Power of Atoms" at London's Royal Institution of Great Britain in . He introduced a colored set of four croquet balls to represent atoms (hydrogen, oxygen, chlorine and nitrogen), implanted with a fixed number of sticks corresponding to each atom's valence. Thus we distinguish the chlorine atom as univalent, […]