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Walsh Diagram of an HAH molecule. Walsh diagrams, often called angular coordinate diagrams or correlation diagrams, are representations of calculated orbital binding energies of a molecule versus a distortion coordinate (bond angles), used for making quick predictions about the geometries of small molecules.
Figure 6:Reaction Coordinate Diagrams showing reactions with 0, 1 and 2 intermediates: The double-headed arrow shows the first, second and third step in each reaction coordinate diagram. In all three of these reactions the first step is the slow step because the activation energy from the reactants to the transition state is the highest.
GCSE Bitesize was launched in January 1998, covering seven subjects. For each subject, a one- or two-hour long TV programme would be broadcast overnight in the BBC Learning Zone block, and supporting material was available in books and on the BBC website. At the time, only around 9% of UK households had access to the internet at home.
This form suggests that the rate-determining step is a reaction between two molecules of NO 2. A possible mechanism for the overall reaction that explains the rate law is: 2 NO 2 → NO 3 + NO (slow) NO 3 + CO → NO 2 + CO 2 (fast) Each step is called an elementary step, and each has its own rate law and molecularity. The elementary steps ...
In August 2018, Ofqual announced that it had intervened to adjust the GCSE Science grade boundaries for students who had taken the "higher tier" paper in its new double award science exams and performed poorly, due to an excessive number of students in danger of receiving a grade of "U" or "unclassified".
In coordination chemistry, a coordinate covalent bond, [1] also known as a dative bond, [2] dipolar bond, [1] or coordinate bond [3] is a kind of two-center, two-electron covalent bond in which the two electrons derive from the same atom. The bonding of metal ions to ligands involves this kind of interaction. [4]
George Hammond developed the postulate during his professorship at Iowa State University. Hammond's postulate (or alternatively the Hammond–Leffler postulate), is a hypothesis in physical organic chemistry which describes the geometric structure of the transition state in an organic chemical reaction. [1]
Principle of chemical precipitation in aqueous solution. In an aqueous solution, precipitation is the "sedimentation of a solid material (a precipitate) from a liquid solution".