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  2. Hydrogen bond - Wikipedia

    en.wikipedia.org/wiki/Hydrogen_bond

    The general notation for hydrogen bonding is Dn−H···Ac, where the solid line represents a polar covalent bond, and the dotted or dashed line indicates the hydrogen bond. [6] The most frequent donor and acceptor atoms are nitrogen (N), oxygen (O), and fluorine (F), due to their high electronegativity and ability to engage in stronger ...

  3. Molecular vibration - Wikipedia

    en.wikipedia.org/wiki/Molecular_vibration

    A molecular vibration is a periodic motion of the atoms of a molecule relative to each other, such that the center of mass of the molecule remains unchanged. The typical vibrational frequencies range from less than 10 13 Hz to approximately 10 14 Hz, corresponding to wavenumbers of approximately 300 to 3000 cm −1 and wavelengths of approximately 30 to 3 μm.

  4. Infrared spectroscopy correlation table - Wikipedia

    en.wikipedia.org/wiki/Infrared_spectroscopy...

    Bond Type of bond Specific type of bond Absorption peak (cm −1) Appearance C─H alkyl methyl 1260 strong 1380 weak 2870 medium to strong 2960 medium to strong methylene: 1470 strong 2850 medium to strong 2925 medium to strong methine: 2890 weak vinyl: C═CH 2: 900 strong 2975 medium 3080 medium C═CH 3020 medium monosubstituted alkenes ...

  5. File:Hydrogen bond arrangements in Schellman loops.pdf

    en.wikipedia.org/wiki/File:Hydrogen_bond...

    You are free: to share – to copy, distribute and transmit the work; to remix – to adapt the work; Under the following conditions: attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made.

  6. Hydrogen line - Wikipedia

    en.wikipedia.org/wiki/Hydrogen_line

    A hydrogen atom with proton and electron spins aligned (top) undergoes a flip of the electron spin, resulting in emission of a photon with a 21 cm wavelength (bottom) The hydrogen line, 21 centimeter line, or H I line [a] is a spectral line that is created by a change in the energy state of solitary, electrically neutral hydrogen atoms.

  7. Electromagnetic absorption by water - Wikipedia

    en.wikipedia.org/wiki/Electromagnetic_absorption...

    In both liquid water and ice clusters, low-frequency vibrations occur, which involve the stretching (TS) or bending (TB) of intermolecular hydrogen bonds (O–H•••O). Bands at wavelengths λ = 50-55 μm or 182-200 cm −1 (44 μm, 227 cm −1 in ice) have been attributed to TS, intermolecular stretch, and 200 μm or 50 cm −1 (166 μm ...

  8. Hydrogen maser - Wikipedia

    en.wikipedia.org/wiki/Hydrogen_maser

    The amount of energy needed to reverse the spin of the electron is equivalent to a photon at the frequency of 1.420 405 751 768 GHz, [1] which corresponds to the 21 cm line in the hydrogen spectrum. Hydrogen masers are very complex devices and sell for as much as US$235,000 . [ 2 ]

  9. Bond graph - Wikipedia

    en.wikipedia.org/wiki/Bond_graph

    Bond graphs are multi-energy domain (e.g. mechanical, electrical, hydraulic, etc.) and domain neutral. This means a bond graph can incorporate multiple domains seamlessly. The bond graph is composed of the "bonds" which link together "single-port", "double-port" and "multi-port" elements (see below for details).