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  2. Isotopes of hydrogen - Wikipedia

    en.wikipedia.org/wiki/Isotopes_of_hydrogen

    Hydrogen (1 H) has three naturally occurring isotopes: 1 H, 2 H, and 3 H. 1 H and 2 H are stable, while 3 H has a half-life of 12.32(2) years. [3] [nb 1] Heavier isotopes also exist; all are synthetic and have a half-life of less than 1 zeptosecond (10 −21 s). [4] [5] Of these, 5 H is the least stable, while 7 H is the most.

  3. Resolution (chromatography) - Wikipedia

    en.wikipedia.org/wiki/Resolution_(chromatography)

    where t R is the retention time and w b is the peak width at baseline. The bigger the time-difference and/or the smaller the bandwidths, the better the resolution of the compounds. The bigger the time-difference and/or the smaller the bandwidths, the better the resolution of the compounds.

  4. Bond valence method - Wikipedia

    en.wikipedia.org/wiki/Bond_valence_method

    The bond valence method or mean method (or bond valence sum) (not to be mistaken for the valence bond theory in quantum chemistry) is a popular method in coordination chemistry to estimate the oxidation states of atoms. It is derived from the bond valence model, which is a simple yet robust model for validating chemical structures with ...

  5. Structural formula - Wikipedia

    en.wikipedia.org/wiki/Structural_formula

    Skeletal structural formula of Vitamin B 12.Many organic molecules are too complicated to be specified by a molecular formula.. The structural formula of a chemical compound is a graphic representation of the molecular structure (determined by structural chemistry methods), showing how the atoms are connected to one another. [1]

  6. Glossary of chemical formulae - Wikipedia

    en.wikipedia.org/wiki/Glossary_of_chemical_formulae

    Chemical formula Synonyms CAS number Ac 2 O 3: actinium(III) oxide: 12002-61-8 AgBF 4: Silver tetrafluoroborate: 14104-20-2 AgBr: silver bromide: 7785-23-1 AgBrO: silver hypobromite

  7. Heavy water - Wikipedia

    en.wikipedia.org/wiki/Heavy_water

    This is because hydrogen atoms (1 H and 2 H) are rapidly exchanged between water molecules. Water containing 50% 1 H and 50% 2 H in its hydrogen, is actually about 50% HDO and 25% each of H 2 O and D 2 O, in dynamic equilibrium. In normal water, about 1 molecule in 3,200 is HDO (one hydrogen in 6,400 is 2 H), and heavy water molecules (D

  8. RICE chart - Wikipedia

    en.wikipedia.org/wiki/RICE_chart

    An ICE table or RICE box or RICE chart is a tabular system of keeping track of changing concentrations in an equilibrium reaction. ICE stands for initial, change, equilibrium . It is used in chemistry to keep track of the changes in amount of substance of the reactants and also organize a set of conditions that one wants to solve with. [ 1 ]

  9. Direct methods (crystallography) - Wikipedia

    en.wikipedia.org/wiki/Direct_methods...

    The key step was taken by Hauptman and Karle, who developed a practical method to employ the Sayre equation for which they were awarded the 1985 Nobel prize in Chemistry. [1] The Nobel Prize citation was "for their outstanding achievements in the development of direct methods for the determination of crystal structures." [1]