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Double substitutions of the phenyl rings are known to occur, even with conversions well below 100%. Crosslinking reactions are also found, where condensation of two sulfonic acid groups yields a sulfonyl crosslink. On the other hand, the use of milder conditions such as acetyl sulfate leads to incomplete sulfonation.
The Bohr model of the hydrogen atom (Z = 1) or a hydrogen-like ion (Z > 1), where the negatively charged electron confined to an atomic shell encircles a small, positively charged atomic nucleus and where an electron jumps between orbits, is accompanied by an emitted or absorbed amount of electromagnetic energy (hν). [1]
Sequential double ionization is a process of formation of doubly charged ions consisting of two single-electron ionization events: the first electron is removed from a neutral atom/molecule (leaving a singly charged ion in the ground state or an excited state) followed by detachment of the second electron from the ion. [4]
Illustration of the Jaynes–Cummings model. An atom in an optical cavity is shown as red dot on the top left. The energy levels of the atom that couple to the field mode within the cavity are shown in the circle on the bottom right. Transfer between the two states causes photon emission (absorption) by the atom into (out of) the cavity mode.
The charge of the resulting ions is a major factor in the strength of ionic bonding, e.g. a salt C + A − is held together by electrostatic forces roughly four times weaker than C 2+ A 2− according to Coulomb's law, where C and A represent a generic cation and anion respectively. The sizes of the ions and the particular packing of the ...
Marcus employs a classical, purely electrostatic model. The charge (many elementary charges) may be transferred in any portion from one body to another. Marcus separates the fast electron polarisation P e and the slow atom and orientation polarisation P u of the solvent on grounds of their time constants differing several orders of magnitude.
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.
Though experimental evidence led to the abandonment of Thomson's plum pudding model as a complete atomic model, irregularities observed in numerical energy solutions of the Thomson problem have been found to correspond with electron shell-filling in naturally occurring atoms throughout the periodic table of elements.