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  2. Rutherford scattering experiments - Wikipedia

    en.wikipedia.org/wiki/Rutherford_scattering...

    In 1909 Robert A. Millikan provided a more accurate measurement of 1.5924 × 10 −19 C, only 0.6% off the current accepted measurement. Jean Perrin in 1909 measured the mass of the hydrogen atom to be 1.43 × 10 −27 kg , [ 66 ] and if an alpha particle is four times as heavy as that, it would have an absolute mass of 5.72 × 10 −27 kg .

  3. Crossover experiment (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Crossover_experiment...

    Crossover experiments allow for experimental study of a reaction mechanism. Mechanistic studies are of interest to theoretical and experimental chemists for a variety of reasons including prediction of stereochemical outcomes, optimization of reaction conditions for rate and selectivity, and design of improved catalysts for better turnover number, robustness, etc. [6] [7] Since a mechanism ...

  4. Jablonski diagram - Wikipedia

    en.wikipedia.org/wiki/Jablonski_diagram

    The changes between these levels are called "transitions" and are plotted on the Jablonski diagram. Radiative transitions involve either the absorption or emission of a photon. As mentioned above, these transitions are denoted with solid arrows with their tails at the initial energy level and their tips at the final energy level.

  5. Glossary of chemistry terms - Wikipedia

    en.wikipedia.org/wiki/Glossary_of_chemistry_terms

    Also acid ionization constant or acidity constant. A quantitative measure of the strength of an acid in solution expressed as an equilibrium constant for a chemical dissociation reaction in the context of acid-base reactions. It is often given as its base-10 cologarithm, p K a. acid–base extraction A chemical reaction in which chemical species are separated from other acids and bases. acid ...

  6. Tacticity - Wikipedia

    en.wikipedia.org/wiki/Tacticity

    For example, when this probability is 0.25 then the probability of finding: an isotactic triad is P m 2, or 0.0625; an heterotactic triad is 2P m (1–P m), or 0.375; a syndiotactic triad is (1–P m) 2, or 0.5625; with a total probability of 1. Similar relationships with diads exist for tetrads. [5]: 357

  7. Limiting reagent - Wikipedia

    en.wikipedia.org/wiki/Limiting_reagent

    If in fact 18 mol O 2 are present, there will be an excess of (18 - 11.25) = 6.75 mol of unreacted oxygen when all the benzene is consumed. Benzene is then the limiting reagent. This conclusion can be verified by comparing the mole ratio of O 2 and C 6 H 6 required by the balanced equation with the mole ratio actually present:

  8. Ball-and-stick model - Wikipedia

    en.wikipedia.org/wiki/Ball-and-stick_model

    In chemistry, the ball-and-stick model is a molecular model of a chemical substance which displays both the three-dimensional position of the atoms and the bonds between them. [1] The atoms are typically represented by spheres, connected by rods which represent the bonds.

  9. Arrow pushing - Wikipedia

    en.wikipedia.org/wiki/Arrow_pushing

    Arrow pushing or electron pushing is a technique used to describe the progression of organic chemistry reaction mechanisms. [1] It was first developed by Sir Robert Robinson.In using arrow pushing, "curved arrows" or "curly arrows" are drawn on the structural formulae of reactants in a chemical equation to show the reaction mechanism.