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  2. Benson group increment theory - Wikipedia

    en.wikipedia.org/wiki/Benson_group_increment_theory

    Heats of formations are intimately related to bond-dissociation energies and thus are important in understanding chemical structure and reactivity. [2] Furthermore, although the theory is old, it still is practically useful as one of the best group-contribution methods aside from computational methods such as molecular mechanics .

  3. Radical (chemistry) - Wikipedia

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

    Radical elimination can be viewed as the reverse of radical addition. In radical elimination, an unstable radical compound breaks down into a spin-paired molecule and a new radical compound. Shown below is an example of a radical elimination reaction, where a benzoyloxy radical breaks down into a phenyl radical and a carbon dioxide molecule. [7]

  4. Trivalent group 14 radicals - Wikipedia

    en.wikipedia.org/wiki/Trivalent_group_14_radicals

    A trivalent group 14 radical (also known as a trivalent tetrel radical) is a molecule that contains a group 14 element (E = C, Si, Ge, Sn, Pb) with three bonds and a free radical, having the general formula of R 3 E•. Such compounds can be categorized into three different types, depending on the structure (or equivalently the orbital in which ...

  5. nth root - Wikipedia

    en.wikipedia.org/wiki/Nth_root

    An unresolved root, especially one using the radical symbol, is sometimes referred to as a surd [2] or a radical. [3] Any expression containing a radical, whether it is a square root, a cube root, or a higher root, is called a radical expression , and if it contains no transcendental functions or transcendental numbers it is called an algebraic ...

  6. Radical clock - Wikipedia

    en.wikipedia.org/wiki/Radical_clock

    In chemistry, a radical clock is a chemical compound that assists in the indirect methodology to determine the kinetics of a free-radical reaction. The radical-clock compound itself reacts at a known rate, which provides a calibration for determining the rate of another reaction.

  7. Distonic ion - Wikipedia

    en.wikipedia.org/wiki/Distonic_ion

    A distonic ion, showing that the molecule's radical site and charge are in different locations. Distonic ions are chemical species that contain ionic charges and radical sites in different locations (on separate atoms), unlike regular radicals where the formal charge and unpaired electron are in the same location. [1]

  8. Mass spectral interpretation - Wikipedia

    en.wikipedia.org/wiki/Mass_spectral_interpretation

    In the spectrum for toluene for example, the molecular ion peak is located at 92 m/z corresponding to its molecular mass. Molecular ion peaks are also often preceded by an M-1 or M-2 peak resulting from loss of a hydrogen radical or dihydrogen, respectively. Here, M refers to the molecular mass of the compound.

  9. Atomic radii of the elements (data page) - Wikipedia

    en.wikipedia.org/wiki/Atomic_radii_of_the...

    Note: All measurements given are in picometers (pm). For more recent data on covalent radii see Covalent radius.Just as atomic units are given in terms of the atomic mass unit (approximately the proton mass), the physically appropriate unit of length here is the Bohr radius, which is the radius of a hydrogen atom.