Linus Pauling in 1987.		Chemical bonding theories John Dalton said atoms join to form molecules, while Archibald Scott Couper and August Kekulé von Stradonitz explored the structures of molecules, but that still left the question of what makes atoms join in the first place. The discovery of the electron made modern understanding of chemical bonding possible. Gilbert Newton Lewis (1875–1946) formulated notions of electron sharing between atoms and the octet rule. These notions were joined by the concept of resonance, devised by Linus Carl Pauling (1901–1994), and eventually by molecular orbital theory to help us understand chemical bonding.