|
Ryutaro Tsuchida
Ryutaro Tsuchida (槌田·龍太郎; 1903-1962) was a Japanese chemist. Tsuchida graduated from Tokyo University in (昭和3年，Shōwa era 3rd) 1928. In June 1935, he established a fifth course at Osaka University. In 1939, he originally proposed the correlation between molecular geometry and number of valence electron pairs (both shared and unshared pairs). This concept was later developed into the VSEPR theory Valence shell electron pair repulsion (VSEPR) theory ( , ) is a conceptual model, model used in chemistry to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms. It is also named the Gill ... of molecular geometry. References 1903 births 1962 deaths 20th-century Japanese chemists Scientists from Kyoto {{chemist-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kyoto
Kyoto ( or ; Japanese language, Japanese: , ''Kyōto'' ), officially , is the capital city of Kyoto Prefecture in the Kansai region of Japan's largest and most populous island of Honshu. , the city had a population of 1.46 million, making it the List of cities in Japan, ninth-most populous city in Japan. More than half (56.8%) of Kyoto Prefecture's population resides in the city. The city is the cultural anchor of the substantially larger Greater Kyoto, a metropolitan statistical area (MSA) home to a census-estimated 3.8 million people. It is also part of the even larger Keihanshin, Keihanshin metropolitan area, along with Osaka and Kobe. Kyoto is one of the oldest municipalities in Japan, having been chosen in 794 as the new seat of Japan's imperial court by Emperor Kanmu. The original city, named Heian-kyō, was arranged in accordance with traditional Chinese feng shui following the model of the ancient Chinese capitals of Chang'an and Luoyang. The emperors of Japan ruled fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osaka University
The , abbreviated as UOsaka or , is a List of national universities in Japan, national research university in Osaka, Japan. The university traces its roots back to Edo period, Edo-era institutions Tekijuku (1838) and Kaitokudō, Kaitokudo (1724), and was officially established in 1931 as the sixth of the Imperial Universities in Japan, with two faculties: science and medicine. Following the Educational reform in occupied Japan, post-war educational reform, it merged with three pre-war Higher school (Japan), higher schools, reorganizing as a comprehensive university with five faculties: science, medicine, letters, law and economics, and engineering. After the merger with Osaka University of Foreign Studies in 2007, UOsaka became the largest national university in Japan by undergraduate enrollment. The official name of the university in English has been changed from "Osaka University" to "The University of Osaka (UOsaka)" as of April 2025. UOsaka is one of the most productive researc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VSEPR Theory
Valence shell electron pair repulsion (VSEPR) theory ( , ) is a conceptual model, model used in chemistry to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms. It is also named the Gillespie-Nyholm theory after its two main developers, Ronald Gillespie and Ronald Sydney Nyholm, Ronald Nyholm. The premise of VSEPR is that the valence electron pairs surrounding an atom tend to repel each other. The greater the repulsion, the higher in energy (less stable) the molecule is. Therefore, the VSEPR-predicted molecular geometry of a molecule is the one that has as little of this repulsion as possible. Gillespie has emphasized that the electron-electron repulsion due to the Pauli exclusion principle is more important in determining molecular geometry than the electrostatic repulsion. The insights of VSEPR theory are derived from topological analysis of the electron density of molecules. Such quantum chemical topology (QCT) metho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Tokyo
The University of Tokyo (, abbreviated as in Japanese and UTokyo in English) is a public research university in Bunkyō, Tokyo, Japan. Founded in 1877 as the nation's first modern university by the merger of several pre-westernisation era institutions, its direct precursors include the '' Tenmongata'', founded in 1684, and the Shōheizaka Institute. Although established under its current name, the university was renamed in 1886 and was further retitled to distinguish it from other Imperial Universities established later. It served under this name until the official dissolution of the Empire of Japan in 1947, when it reverted to its original name. Today, the university consists of 10 faculties, 15 graduate schools, and 11 affiliated research institutes. As of 2023, it has a total of 13,974 undergraduate students and 14,258 graduate students. The majority of the university's educational and research facilities are concentrated within its three main Tokyo campuses: Hongō, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shōwa Era
The was a historical period of History of Japan, Japanese history corresponding to the reign of Emperor Shōwa (Hirohito) from December 25, 1926, until Death and state funeral of Hirohito, his death on January 7, 1989. It was preceded by the Taishō era and succeeded by the Heisei era. The pre-1945 and post-war Shōwa periods are almost completely different states: the pre-1945 Shōwa era (1926–1945) concerns the Empire of Japan, and the post-1945 Shōwa era (1945–1989) concerns the modern-day Japan. Before 1945, Japan moved into political Statism in Shōwa Japan, totalitarianism, ultranationalism and statism, culminating in Japan's Second Sino-Japanese War, invasion of China in 1937, part of a global period of social upheavals and conflicts such as the Great Depression and the Pacific War. Surrender of Japan, Defeat in the Pacific War brought about radical change in Japan. For the first and only time in its history, Japan was occupation of Japan, occupied by foreign power ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Geometry
Molecular geometry is the three-dimensional arrangement of the atoms that constitute a molecule. It includes the general shape of the molecule as well as bond lengths, bond angles, torsional angles and any other geometrical parameters that determine the position of each atom. Molecular geometry influences several properties of a substance including its reactivity, polarity, phase of matter, color, magnetism and biological activity. The angles between bonds that an atom forms depend only weakly on the rest of a molecule, i.e. they can be understood as approximately local and hence transferable properties. Determination The molecular geometry can be determined by various spectroscopic methods and diffraction methods. IR, microwave and Raman spectroscopy can give information about the molecule geometry from the details of the vibrational and rotational absorbance detected by these techniques. X-ray crystallography, neutron diffraction and electron diffraction can g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valence Electron
In chemistry and physics, valence electrons are electrons in the outermost shell of an atom, and that can participate in the formation of a chemical bond if the outermost shell is not closed. In a single covalent bond, a shared pair forms with both atoms in the bond each contributing one valence electron. The presence of valence electrons can determine the element's chemical properties, such as its valence—whether it may bond with other elements and, if so, how readily and with how many. In this way, a given element's reactivity is highly dependent upon its electronic configuration. For a main-group element, a valence electron can exist only in the outermost electron shell; for a transition metal, a valence electron can also be in an inner shell. An atom with a closed shell of valence electrons (corresponding to a noble gas configuration) tends to be chemically inert. Atoms with one or two valence electrons more than a closed shell are highly reactive due to the relativ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1903 Births
Events January * January 1 – Edward VII is proclaimed Emperor of India. * January 10 – The Aceh Sultanate was fully annexed by the Dutch East Indies, Dutch forces, deposing the last sultan, marking the end of the Aceh War that have lasted for almost 30 years. * January 19 – The first west–east transatlantic radio broadcast is made from the United States to England (the first east–west broadcast having been made in 1901#December, 1901). February * February 13 – Venezuelan crisis of 1902–03, Venezuelan crisis: After agreeing to arbitration in Washington, the United Kingdom, Germany and Italy reach a settlement with Venezuela resulting in the Washington Protocols. The naval blockade that began in 1902 ends. * February 23 – Cuba leases Guantánamo Bay to the United States "in perpetuity". March * March 2 – In New York City, the Martha Washington Hotel, the first hotel exclusively for women, opens. * March 3 – The British Admir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1962 Deaths
The year saw the Cuban Missile Crisis, which is often considered the closest the world came to a Nuclear warfare, nuclear confrontation during the Cold War. Events January * January 1 – Samoa, Western Samoa becomes independent from New Zealand. * January 3 – The office of Pope John XXIII announces the excommunication of Fidel Castro for preaching communism and interfering with Catholic churches in Cuba. * January 8 – Harmelen train disaster: 93 die in the worst Netherlands, Dutch rail disaster. * January 9 – Cuba and the Soviet Union sign a trade pact. * January 12 – The Indonesian Army confirms that it has begun operations in West Irian. * January 13 – People's Socialist Republic of Albania, Albania allies itself with the People's Republic of China. * January 15 ** Portugal abandons the United Nations General Assembly due to the debate over Angola. ** French designer Yves Saint Laurent (designer), Yves Saint Laurent launches Yves Saint Lau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
