Linus Pauling was born in Portland, Oregon, in 1901. He graduated from Oregon State College in 1922 and obtained his Ph.D. in chemistry in 1925 from the California Institute of Technology. After a period of study in Europe, he became a professor at the California Institute of Technology in 1927. He remained there for the rest of his academic career.

Pauling did much to develop our understanding of the chemical bond. Among the important concepts that he introduced were electronegativity and resonance structures. He was one of a very small number of chemists who seriously considered the possibility that the noble gases might form compounds. In 1939 he published his ideas on chemical bonding in a book entitled The Nature of the Chemical Bond. This book proved to be one of the most influential chemistry books of the century. In 1954 Pauling was awarded the Nobel Prize in chemistry for his work on molecular structure.

In the 1950s, Pauling turned to studying the structures of biopolymers. He was one of the first to suggest that protein molecules have a helical shape. Pauling’s claim that large doses of vitamin C are effective in preventing the common cold has attracted attention since 1970. However, research has failed to support this claim. After World War II, Pauling became a passionate supporter of nuclear disarmament. In 1962 he was awarded the Nobel Peace Prize, thus becoming the second person in history to win two Noble Prizes. Pauling died in 1994.