Erich Armand Arthur Joseph Hückel (August 9, 1896 - February 16, 1980) was a German physicist and physical chemist. He is known for two major contributions: August 9 is the 221st day of the year in the Gregorian Calendar (222nd in leap years), with 144 days remaining. ... 1896 was a leap year starting on Wednesday (see link for calendar). ... February 16 is the 47th day of the year in the Gregorian Calendar. ... Physics (from the Greek, φυσικός (physikos), natural, and φύσις (physis), Nature) is the science of Nature in the broadest sense. ... Physical chemistry is the study of the physical basis of chemical systems and processes. ...

• The Debye-Hückel theory of electrolytic solutions
• The Hückel method of approximate molecular orbital (MO) calculations on pi electron systems.

Hückel was born in the Charlottenburg suburb of Berlin. He studied physics and mathematics from 1914 to 1921 at the University of Göttingen. Peter Joseph William Debye (March 24, 1884 - November 2, 1966) (born Petrus Josephus Wilhelmus Debije) was a Dutch physical chemist. ... An electrolyte is a substance which dissociates free ions when dissolved (or molten), to produce an electrically conductive medium. ... This article or section should be merged with solvent, soluble, and solubility equilibrium Dissolving table salt in water In chemistry, a solution is one or more substance (the solute) dissolved in another substance (the solvent) forming a homogenous mixture. ... In quantum chemistry, molecular orbitals are the statistical states electrons can have within molecules. ... Geometry of the water molecule Molecules have fixed equilibrium geometries--bond lengths and angles--that are dictated by the laws of quantum mechanics. ... Physics (from the Greek, φυσικός (physikos), natural, and φύσις (physis), Nature) is the science of Nature in the broadest sense. ... Mathematics, often abbreviated maths in Commonwealth English and math in American English, is the study of abstraction. ... 1914 is a common year starting on Thursday. ... The Georg-August University of Göttingen (Georg-August-Universität Göttingen, often called the Georgia Augusta) was founded in 1734 by George II, King of Great Britain and Elector of Hanover, and opened in 1737. ...

On receiving his doctorate, he became an assistant at Göttingen, but soon became an assistant to Peter Debye at Zürich. It was there that he and Debye developed their theory (the Debye-Hückel theory, in 1923) of electrolytic solutions, elucidating the behavior of strong electrolytes to account for their conductivity by considering interionic forces. Doctor of Philosophy (Ph. ... Peter Joseph William Debye (March 24, 1884 - November 2, 1966) (born Petrus Josephus Wilhelmus Debije) was a Dutch physical chemist. ... Zürich IPA (in English often Zurich, which is also the standard French form of the name) is the largest city in Switzerland (population: 364,558 in 2002; population of urban area: 1,091,732) and capital of the canton of Zürich. ...

In 1928 and 1929 he spent time in England and Denmark, working briefly with Niels Bohr. Then he became a faculty member at the Technische Hochschule in Stuttgart, serving until 1935, when he went to Phillips University in Marburg, where he remained until 1961. Royal motto: Dieu et mon droit (French: God and my right) Official language None; English is de facto Capital London Capitals coordinates 51° 30 N, 0° 10 W Largest city London Area  - Total Ranked 1st UK 130,395 km² Population  - Total (2001)  - Density Ranked 1st UK 49,138,831... The Kingdom of Denmark is geographically the smallest Nordic country and is part of the European Union. ... Niels Bohr Niels Henrik David Bohr (October 7, 1885 – November 18, 1962) was a Danish physicist who made essential contributions to understanding atomic structure and quantum mechanics. ... Stuttgart is a city located in southern Germany, it is the capital of the state of Baden-Württemberg, and has a population of approximately 600,000 as of June 2004. ... Marburg is a town in Hessen, Germany, on the Lahn river. ... 1961 (As MAD Magazine pointed out on its first cover for the year) was the first upside-down year - i. ...

Eventually his interests moved to the use of quantum mechanics to deal with organic molecules. In 1931 he formulated the "Hückel rule" for determining whether ring molecules would show aromatic properties, and in 1937 developed his approximate MO theory for unsaturated organic molecules. This is still used as an approximation, though the more precise Pariser-Parr-Pople method succeeded it after its publication separately by Pariser and Parr and by Pople in 1953, for more accurate calculations. An extension of the Hückel MO theory was also developed by Roald Hoffmann for nonplanar molecules in 1963. Fig. ... Organic chemistry is the scientific study of the structure, properties, composition, reactions, and synthesis of organic compounds. ... In science, a molecule is the smallest particle of a pure chemical substance that still retains its chemical composition and properties. ... 1931 is a common year starting on Thursday. ... The term aromatic compound may also refer to: any organic compound possessing a strong olfactory aroma aromatic hydrocarbons (originally named as a subset of the above; however, aromatic hydrocarbons do not necessarily possess any smell whatsoever) ... 1937 was a common year starting on Friday (link will take you to calendar). ... Rudolph Pariser (born December 8, 1923) is a physical chemist and polymer chemist. ... Robert Ghormley Parr (born September 22, 1921) is a theoretical chemist. ... Sir John Anthony Pople (October 31, 1925 - March 15, 2004) was a theoretical chemist. ... 1953 is a common year starting on Thursday. ... Roald Hoffmann (born July 18, 1937) is a Polish theoretical chemist. ... Events January-February January 11 - The Whisky A Go-Go night club in Los Angeles, the first disco in the USA, is opened. ...