Nineteen+Fifty+to+Present

en.wikipedia.org/wiki/Linus_Pauling Linus Pauling was an American chemist born on February 28, 1901. Pauling was " among the first scientists to work in the fields of quantum chemistry, molecular biology, and orthomolecular medicine. He is one of only four individuals to have won multiple Nobel Prizes".(en.wikipedia.org/wiki/Linus_Pauling). "Part of Pauling's work on the nature of the chemical bond led to his introduction of the concept of orbital hybridization.[73] While it is normal to think of the electrons in an atom as being described by orbitals of types such as //s// and //p//, it turns out that in describing the bonding in molecules, it is better to construct functions that partake of some of the properties of each. Thus the one 2s and three 2p orbitals in a carbon atom can be combined to make four equivalent orbitals (called sp³ hybrid orbitals), which would be the appropriate orbitals to describe carbon compounds such as methane, or the 2s orbital may be combined with two of the 2p orbitals to make three equivalent orbitals (called sp² hybrid orbitals), with the remaining 2p orbital unhybridized, which would be the appropriate orbitals to describe certain unsaturated carbon compounds such as ethylene."(en.wikipedia.org/wiki/Linus_Pauling). Pauling passed away on August 19, 1994.

en.wikipedia.org/wiki/Dorothy_Crowfoot_Hodgkin Dorothy Hodgkin was a British chemist who was born on May 10, 1910. "She advanced the technique of X-ray crystallography, a method used to determine the three dimensional structures of biomolecules. Among her most influential discoveries are the confirmation of the structure of penicillin that Ernst Boris Chain had previously surmised, and then the structure of vitamin B12, for which she was awarded the Nobel Prize in Chemistry. In 1969, after 35 years of work and five years after winning the Nobel Prize, Hodgkin was able to decipher the structure of insulin. X-ray crystallography became a widely used tool and was critical in later determining the structure of many biological molecules such as DNA where knowledge of structure is critical to an understanding of function. She is regarded as one of the foremost scientists in the field of X-Ray crystallography studies of natural molecules. Besides her extraordinary scientific abilities, she was unassuming, communicative and passionate about social inequalities and peace."(en.wikipedia.org/wiki/Dorothy_Crowfoot_Hodgkin). She passed away on July 29, 1994.

en.wikipedia.org/wiki/Helen_Murray_Free Helen Murray Free is a retired American chemist who was born on February 20, 1923. "She is most known for her creation of many self-testing systems for diabetes while working atMiles Laboratories, which is now owned by Bayer AG. She currently is an Adjunct Professor of Management at Indiana University South Bend, and a Consultant for Bayer AG.....Free worked with her husband to move the tests from tablets to strips, introducing Clinistix (the famous “dip-and-read” test) in 1956. Several other testing strips were developed and added to the market, including Uristix, Ketostix, Dextrostox, Labstix, and a still-current product, Multistix.[|[2]] These products are still used today.....In 1993 she was elected president of the ACS. As president, Free considered her top priority to be to raise public awareness of the positive role chemistry has played in our lives. The ACS named an award in her honor, the Helen M. Free Award in Public Outreach. In 2000 she was inducted into the National Inventor's Hall of Fame."(en.wikipedia.org/wiki/Helen_Murray_Free).