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Kekulé's idea of assigning certain atoms to certain positions within the molecule, and schematically connecting them using what he called their " Verwandtschaftseinheiten " (" affinity units ", now called " valences " or " bonds "), was based largely on evidence from chemical reactions, rather than on instrumental methods that could peer directly into the molecule, such as X-ray crystallography.
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Kekulé's and idea
The idea that the number of valences of a given element was invariant was a key component of Kekulé's version of structural chemistry.
Kekulé's and atoms
) However, through a misunderstanding with Wurtz, Kekulé's paper appeared in print first, in May 1858, and so Kekulé captured the priority for the discovery of the self-linking of carbon atoms.
Kekulé's and what
However, most chemists followed Kekulé's lead in pursuing and developing what some have called " classical " structure theory, which was modified after the discovery of electrons ( 1897 ) and the development of quantum mechanics ( in the 1920s ).
Kekulé's and their
After Kekulé's proposal for benzene structure in 1865, he suggested a " Partial Valence Hypothesis ", which concerned double and triple carbon-carbon bonds with which he explains their particular reactivity.
Kekulé's and was
Kekulé's most famous work was on the structure of benzene.
The counting of possible isomers for diderivatives was however criticized by Albert Ladenburg, a former student of Kekulé, who argued that Kekulé's 1865 structure implied two distinct " ortho " structures, depending on whether the substituted carbons are separated by a single or a double bond.
Kekulé's and on
Such physical methods of structural determination had not yet been developed, so chemists of Kekulé's day had to rely almost entirely on so-called " wet " chemistry.
Kekulé's and from
Couper's research differed from Kekulé's in several ways.
Kekulé's and .
The French accent had apparently been added to the name by Kekulé's father during the Napoleonic occupation of Hesse by France, in order to ensure that French speakers pronounced the third syllable.
idea and assigning
The term is used to embrace two ideas: " human speciesism ," which is the exclusion of all nonhuman animals from the protections afforded to humans, and the more general idea of assigning value to a being on the basis of their species, so that human beings favouring rights for chimpanzees over rights for dogs because of human-chimpanzee similarities, would be an example of " human-chimpanzee speciesism.
Interestingly, Bayes actually states his question in a way that might make the idea of assigning a probability distribution to a parameter palatable to a frequentist.
The main idea is to assign to each vertex the color that differs from the color of its parent in the depth-first search tree, assigning colors in a preorder traversal of the depth-first-search tree.
15 % endorsed the idea of assigning a child a third sex ( neither male nor female ).
Hitchcock was under contract to David O. Selznick, so he first pitched the idea for the film to him ; Selznick gave the okay for a script to be written, assigning John Houseman to keep an eye on its progress and direction.
Theon quotes a poem by Alexander of Ephesus assigning specific pitches in the chromatic scale to each planet, an idea that would retain its popularity for a millennium thereafter.
The basic idea of list scheduling is to make an ordered list of processes by assigning them some priorities, and then repeatedly execute the following two steps until a valid schedule is obtained:
idea and certain
This whole development is certain to be of interest to the readers, for the idea has so often been mentioned, somewhat wistfully.
This last point is important because if high school pupils are aware that few, if any, graduates who have chosen a certain vocational program have obtained a job as a consequence of the training, the whole idea of relevance disappears.
In the 17th and 18th centuries, chemists provided a physical basis for this idea by showing that certain substances could not be further broken down by chemical methods.
For a reader to assign the title of author upon any written work is to attribute certain standards upon the text which, for Foucault, are working in conjunction with the idea of " the author function ".
Possible purposes might be to generate action, inform, create understanding or communicate a certain idea / point etc.
However this idea is still pursued for certain applications by some companies like Netezza and Oracle ( Exadata ).
Charles Baudelaire, in the later, " metaphysical " phase of dandyism defined the dandy as one who elevates æsthetics to a living religion, that the dandy's mere existence reproaches the responsible citizen of the middle class: " Dandyism in certain respects comes close to spirituality and to stoicism " and " These beings have no other status, but that of cultivating the idea of beauty in their own persons, of satisfying their passions, of feeling and thinking ....
From Weierstrass he derives the idea that we generate the concept of number by counting a certain collection of objects.
Charles de Gaulle described the role he envisaged for the French president when he wrote the modern French constitution, stating the head of state should embody " the spirit of the nation " for the nation itself and the world: une certaine idée de la France ( a certain idea about France ).
The idea that adult humans exhibit certain neotenous ( juvenile ) features, not evinced in the great apes, is about a century old.
Carpenter had observed from close examination of everyday experience that under certain circumstances the mere idea of a muscular movement could be sufficient to produce a reflexive, or automatic, contraction or movement of the muscles involved, albeit in a very small degree.
For George Woodcock this attitude can be also motivated by certain idea of resistance to progress and of rejection of the growing materialism which is the nature of American society in the mid 19th century.
Many of his novels have strong anarchist or libertarian themes, often promoting the idea that new technological advances render certain social conventions obsolete.
Instead, for him, the idea of an " infectious idea " can be a useful conceit if used under certain conditions.
Basically his idea was to add electrons to inflate the spherical Fermi-balloon inside the series of Brillouin-boxes and determine when a certain box would be full.
Players enter at one spot, and exit at another, or the idea may be to reach a certain spot in the maze.
Hart was also not certain that the idea had much merit, and the two therefore separated.
While recognizing that some students will learn certain material faster than others, the standards movement rejects the idea that only a few can succeed.
The idea of rational choice, where people compare the costs and benefits of certain actions, is easy to see in economic theory.
This is the idea that has become dominant ( with certain modifications ) in modern Hinduism.
Recent studies have indicated that some Westerners accept the idea of reincarnation including certain contemporary Christians, modern Neopagans, followers of Spiritism, Theosophists and students of esoteric philosophies such as Kabbalah, and Gnostic and Esoteric Christianity as well as of Indian religions.
Before Sima, histories were written as certain events or certain periods of history of states ; his idea of a general history affected later historiographers like Zheng Qiao ( 鄭樵 ) in writing Tongshi ( 通史 ) and Sima Guang ( 司馬光 ) in writing Zizhi Tongjian ( 資治通鑑 ).
idea and atoms
The idea of covalent bonding can be traced several years before 1919 to Gilbert N. Lewis, who in 1916 described the sharing of electron pairs between atoms.
Similarly, the ancient metaphysical and unfalsifiable idea of the existence of atoms has led to corresponding falsifiable modern theories.
This theory proceeds from the idea of atomic valence, especially the tetravalence of carbon ( which Kekulé announced late in 1857 ) and the ability of carbon atoms to link to each other ( announced in a paper published in May 1858 ), to the determination of the bonding order of all of the atoms in a molecule.
Archibald Scott Couper independently arrived at the idea of self-linking of carbon atoms ( his paper appeared in June 1858 ), and provided the first molecular formulas where lines symbolize bonds connecting the atoms.
Leucippus and his student, Democritus, were the first to develop the theory of atomism – the idea that everything is composed entirely of various imperishable, indivisible elements called atoms.
Haüy's study led to the correct idea that crystals are a regular three-dimensional array ( a Bravais lattice ) of atoms and molecules ; a single unit cell is repeated indefinitely along three principal directions that are not necessarily perpendicular.
Epicurus proposed the idea of ' the space between worlds ' ( metakosmia ) the relatively empty spaces in the infinite void where worlds had not been formed by the joining together of the atoms through their endless motion.
However, a study of Dalton's own laboratory notebooks, discovered in the rooms of the Lit & Phil, concluded that so far from Dalton being led by his search for an explanation of the law of multiple proportions to the idea that chemical combination consists in the interaction of atoms of definite and characteristic weight, the idea of atoms arose in his mind as a purely physical concept, forced upon him by study of the physical properties of the atmosphere and other gases.
In addition, the idea that all atoms of a given element are identical in their physical and chemical properties is not precisely true, as we now know that different isotopes of an element have slightly varying weights.
Einstein adopted the idea and extended it to atoms.
Rabi came up with the idea of using a uniform field instead, with the molecular beam at a glancing angle, so the atoms would be deflected like light through a prism.
Couper's idea that carbon atoms can link to each other following valence regularities was independent of a paper by August Kekulé proposing the same concept.
This led to the original idea for the production of p-nuclei: free protons ( the nuclei of hydrogen atoms are present in stellar plasmas ) should be captured on heavy nuclei ( seed nuclei ) also already present in the stellar plasma ( previously produced in the s-and / or r-process ).
Schrieffer recalls that in January 1957 he was on a subway in New York City when he had an idea of how to describe mathematically the ground state of superconducting atoms.
In the words of Robert Nesbet: " Slater founded the SSMTG with the idea of bringing together a younger generation of students and PostDocs with a common interest in the electronic structure and properties of atoms, molecules and solids.
These complications arise because helium atoms repel each other much more strongly than electrons, but the basic idea is the same.
Kanada also put forward the idea that atoms could be combined in various ways to produce chemical changes in presence of other factors such as heat.
One path to the reciprocal lattice of an arbitrary collection of atoms comes from the idea of scattered waves in the Fraunhofer ( long-distance or lens back-focal-plane ) limit as a Huygens-style sum of amplitudes from all points of scattering ( in this case from each individual atom ).
Valence bond theory now complements molecular orbital ( MO ) theory, which does not adhere to the VB idea that electron pairs are localized between two specific atoms in a molecule but that they are distributed in sets of molecular orbitals which can extend over the entire molecule.
2.133 seconds.