Richard abegg chemist biography template

January 9 is Richard Abegg’s birthday. Abegg was a German chemist who was one of the early researchers of valence theory. His experiments showed a tendency between the maximum and minimum valence levels of elements differed usually by a value of eight. This relationship became known as Abegg’s rule when Gilbert Lewis proposed his octet rules.

Abegg also discovered the principle behind freezing point depression of solvents. The freezing point is at the transition point between the liquid phase and the solid phase of a liquid. It is determined when the vapor pressures of the liquid and solid phases are equal. Abegg found if a solute was added to the solvent, the freezing point would be depressed to a lower temperature.

Abegg was also an avid enthusiast of ballooning. This hobby would ultimately cause his death when he flew his balloon with an engineer and female relative. When the balloon encountered strong winds, they opened the gas valves to cause the balloon to descend. The balloon managed to reach the ground safely and the other two were able to exit the basket. Abegg was caught as a gust of wind as he exited and was crushed by the basket.

Notable Science History Events for January 9

1998 – Kenichi Fukui died.

Fukui was a Japanese chemist who shares the 1981 Nobel Prize in Chemistry with Roald Hoffman for their independent research on the mechanics of chemical reactions. Fukui’s research centered on the outermost electron orbitals of a molecule and their change in shape when they bond during a reaction. He also investigated the reactions involving molecular nitrogen with transition metal complexes.

1950 – Alec Jeffreys was born.

Jeffreys is a British geneticist who developed the process of DNA fingerprinting. DNA fingerprinting, or DNA profiling is the technique used to assist identification of individuals based on their genetic makeup. It is used extensively in crime investigations and parental testing. Several countrie

One of the most interesting developments in the history of chemistry has been the way in which theories of valency have evolved over the years. We are rapidly approaching the centenary of G.N. Lewis’ 1916 article in which he proposed the simple idea that a covalent bond consists of a shared pair of electrons. No doubt there will be celebrations and special issues of various journals that will be motivated by the arrival of this centenary. But as in all celebrations we tend to forget some lesser known contributors who provided important steps towards the eventually adopted theories. Here I would like to recall the work of one of these sub-alterns, the German chemist Richard Abegg.

Abegg had the good fortune of studying and working with Lothar Meyer, Ladenburg, A.W. Hoffman, Ostwald, Arrhenius, and Nernst before his life was tragically cut short at the age of 41 when he died in a ballooning accident. But before this untimely end Abegg provided what was perhaps the most important step in valence theory between the discovery of Mendeleev’s periodic system and G.N. Lewis’ notion of octets of electrons.

After publishing his periodic table in 1969, Mendeleev had noticed that the valences of many elements obeyed an important relationship that has been called his rule of eight. Mendeleev observed that the formulas of hydrides occurred in four forms, namely RH, EH₂, RH₃, EH₄. Meanwhile, with oxygen the following forms are found,

R₂O,     RO,     R₂O₃,    RO₂,     R₂O₅,    RO₃,    R₂O₇,    RO₄

Mendeleev noted that for no element does the sum of the hydrogen and oxygen equivalences exceed eight.

Oxide                          RO₄      R₂O₇    RO₃      R₂O₅        RO₂

Hydride                      none   RH       RH₂     RH₃     EH₄

Significantly, for what is to come, this relationship seems to only apply to elements from just four groups in the periodic table. Mendeleev’s rule remained obscure until