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  2. Prism correction - Wikipedia

    en.wikipedia.org/wiki/Prism_correction

    Thus a prism of 1 Δ would produce 1 cm visible displacement at 100 cm, or 1 meter. This can be represented mathematically as: = ⁡ where is the amount of prism correction in prism dioptres, and is the angle of deviation of the light.

  3. Square antiprismatic molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Square_antiprismatic...

    In chemistry, the square antiprismatic molecular geometry describes the shape of compounds where eight atoms, groups of atoms, or ligands are arranged around a central atom, defining the vertices of a square antiprism.

  4. Edwards equation - Wikipedia

    en.wikipedia.org/wiki/Edwards_equation

    Edwards equation. The Edwards equation in organic chemistry is a two-parameter equation for correlating nucleophilic reactivity, as defined by relative rate constants, with the basicity of the nucleophile (relative to protons) and its polarizability. This equation was first developed by John O. Edwards in 1954 [1] and later revised based on ...

  5. Fine structure - Wikipedia

    en.wikipedia.org/wiki/Fine_structure

    Relativistic corrections (Dirac) to the energy levels of a hydrogen atom from Bohr's model. The fine structure correction predicts that the Lyman-alpha line (emitted in a transition from n = 2 to n = 1) must split into a doublet. The total effect can also be obtained by using the Dirac equation. In this case, the electron is treated as non ...

  6. VSEPR theory - Wikipedia

    en.wikipedia.org/wiki/VSEPR_theory

    Based on the steric number and distribution of Xs and Es, VSEPR theory makes the predictions in the following tables. Main-group elements. For main-group elements, there are stereochemically active lone pairs E whose number can vary between 0 to 3. Note that the geometries are named according to the atomic positions only and not the electron ...

  7. Standard hydrogen electrode - Wikipedia

    en.wikipedia.org/wiki/Standard_hydrogen_electrode

    The hydrogen electrode is based on the redox half cell corresponding to the reduction of two hydrated protons, 2H+(aq), into one gaseous hydrogen molecule, H2 (g). General equation for a reduction reaction: The reaction quotient ( Qr) of the half-reaction is the ratio between the chemical activities ( a) of the reduced form (the reductant, ared ...

  8. Esophoria - Wikipedia

    en.wikipedia.org/wiki/Esophoria

    Esophoria is an eye condition involving inward deviation of the eye, usually due to extra-ocular muscle imbalance. It is a type of heterophoria. Cause. Causes include: Refractive errors; Divergence insufficiency; Convergence excess; this can be due to nerve, muscle, congenital or mechanical anomalies.

  9. UNIQUAC - Wikipedia

    en.wikipedia.org/wiki/UNIQUAC

    UNIQUAC. In statistical thermodynamics, UNIQUAC (a portmanteau of uni versal qua si c hemical) is an activity coefficient model used in description of phase equilibria. [1] [2] The model is a so-called lattice model and has been derived from a first order approximation of interacting molecule surfaces.

  10. Acid dissociation constant - Wikipedia

    en.wikipedia.org/wiki/Acid_dissociation_constant

    e. In chemistry, an acid dissociation constant (also known as acidity constant, or acid-ionization constant; denoted ) is a quantitative measure of the strength of an acid in solution. It is the equilibrium constant for a chemical reaction. known as dissociation in the context of acid–base reactions.

  11. Chemical equation - Wikipedia

    en.wikipedia.org/wiki/Chemical_equation

    A chemical equation is the symbolic representation of a chemical reaction in the form of symbols and chemical formulas.The reactant entities are given on the left-hand side and the product entities are on the right-hand side with a plus sign between the entities in both the reactants and the products, and an arrow that points towards the products to show the direction of the reaction.