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  2. Resonance (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Resonance_(chemistry)

    Contributing structures of the carbonate ion. In chemistry, resonance, also called mesomerism, is a way of describing bonding in certain molecules or polyatomic ions by the combination of several contributing structures (or forms, [1] also variously known as resonance structures or canonical structures) into a resonance hybrid (or hybrid structure) in valence bond theory.

  3. Mesomeric effect - Wikipedia

    en.wikipedia.org/wiki/Mesomeric_effect

    In chemistry, the mesomeric effect (or resonance effect) is a property of substituents or functional groups in a chemical compound. It is defined as the polarity produced in the molecule by the interaction of two pi bonds or between a pi bond and lone pair of electrons present on an adjacent atom. [ 1 ]

  4. Nucleophilic aromatic substitution - Wikipedia

    en.wikipedia.org/wiki/Nucleophilic_aromatic...

    A small percentage of the intermediate loses the chloride to become the product (2,4-dinitrophenol, 3), while the rest return to the reactant (1). Since 2,4-dinitrophenol is in a lower energy state, it will not return to form the reactant, so after some time has passed, the reaction reaches chemical equilibrium that favors the 2,4-dinitrophenol ...

  5. Wolff rearrangement - Wikipedia

    en.wikipedia.org/wiki/Wolff_rearrangement

    A few years later, in an independent study, Schröter observed similar results. [5] The reaction is occasionally called the Wolff-Schröter rearrangement. [ 2 ] The Wolff rearrangement was not commonly used until 20 years after it was discovered, as facile diazo ketone synthesis was unknown until the 1930s. [ 2 ]

  6. Förster resonance energy transfer - Wikipedia

    en.wikipedia.org/wiki/Förster_resonance_energy...

    Jablonski diagram of FRET with typical timescales indicated. The black dashed line indicates a virtual photon.. Förster resonance energy transfer (FRET), fluorescence resonance energy transfer, resonance energy transfer (RET) or electronic energy transfer (EET) is a mechanism describing energy transfer between two light-sensitive molecules (chromophores). [1]

  7. J/psi meson - Wikipedia

    en.wikipedia.org/wiki/J/psi_meson

    The J/ψ (J/psi) meson / ˈ dʒ eɪ ˈ s aɪ ˈ m iː z ɒ n / is a subatomic particle, a flavor-neutral meson consisting of a charm quark and a charm antiquark.Mesons formed by a bound state of a charm quark and a charm anti-quark are generally known as "charmonium" or psions. [1]

  8. End correction - Wikipedia

    en.wikipedia.org/wiki/End_correction

    Hence an end correction is sometimes required to appropriately study its properties. The end correction depends on the radius of the object. An acoustic pipe, such as an organ pipe, marimba, or flute resonates at a specific pitch or frequency. Longer pipes resonate at lower frequencies, producing lower-pitched sounds.

  9. Joint Entrance Examination – Advanced - Wikipedia

    en.wikipedia.org/wiki/Joint_Entrance_Examination...

    The IIT-JEE was first conducted in 1961 as Common Entrance Exam (CEE), coinciding with the 1961 IIT Act. [11] In 1978, the English paper was not considered when ranking participants' performance in the examination. In 1998, the English test was discontinued. In 1997, the IIT-JEE was conducted twice after the question paper was leaked in some ...