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  2. Mesomeric effect - Wikipedia

    en.wikipedia.org/wiki/Mesomeric_effect

    The mesomeric effect as a result of p-orbital overlap (resonance) has absolutely no effect on this inductive effect, as the inductive effect has purely to do with the electronegativity of the atoms and their topology in the molecule (which atoms are connected to which). Specifically the inductive effect is the tendency for the substituents to ...

  3. Helmholtz resonance - Wikipedia

    en.wikipedia.org/wiki/Helmholtz_resonance

    Helmholtz resonance, also known as wind throb, refers to the phenomenon of air resonance in a cavity, an effect named after the German physicist Hermann von Helmholtz. [1] This type of resonance occurs when air is forced in and out of a cavity (the resonance chamber ), causing the air inside to vibrate at a specific natural frequency .

  4. Mössbauer effect - Wikipedia

    en.wikipedia.org/wiki/Mössbauer_effect

    The Mössbauer effect, or recoilless nuclear resonance fluorescence, is a physical phenomenon discovered by Rudolf Mössbauer in 1958. It involves the resonant and recoil -free emission and absorption of gamma radiation by atomic nuclei bound in a solid.

  5. Electrophilic aromatic directing groups - Wikipedia

    en.wikipedia.org/wiki/Electrophilic_aromatic...

    In general, the resonance effect of elements in the third period and beyond is relatively weak. This is mainly because of the relatively poor orbital overlap of the substituent's 3p (or higher) orbital with the 2p orbital of the carbon. Due to a stronger resonance effect and inductive effect than the heavier halogens, fluorine is anomalous.

  6. Schumann resonances - Wikipedia

    en.wikipedia.org/wiki/Schumann_resonances

    The global electromagnetic resonance phenomenon is named after physicist Winfried Otto Schumann who predicted it mathematically in 1952. Schumann resonances are the principal background in the part of the electromagnetic spectrum [2] from 3 Hz through 60 Hz [3] and appear as distinct peaks at extremely low frequencies around 7.83 Hz (fundamental), 14.3, 20.8, 27.3, and 33.8 Hz.

  7. 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.

  8. Resonance - Wikipedia

    en.wikipedia.org/wiki/Resonance

    However, resonance can also be detrimental, leading to excessive vibrations or even structural failure in some cases. [3] All systems, including molecular systems and particles, tend to vibrate at a natural frequency depending upon their structure; this frequency is known as a resonant frequency or resonance frequency.

  9. Kozai mechanism - Wikipedia

    en.wikipedia.org/wiki/Kozai_mechanism

    It also termed an effect, oscillations, cycles, or resonance. This effect causes the orbit's argument of pericenter to oscillate about a constant value, which in turn leads to a periodic exchange between its eccentricity and inclination. The process occurs on timescales much longer than the orbital periods.