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  2. Arrow pushing - Wikipedia

    en.wikipedia.org/wiki/Arrow_pushing

    Arrow pushing or electron pushing is a technique used to describe the progression of organic chemistry reaction mechanisms. [1] It was first developed by Sir Robert Robinson.In using arrow pushing, "curved arrows" or "curly arrows" are drawn on the structural formulae of reactants in a chemical equation to show the reaction mechanism.

  3. Protocol (science) - Wikipedia

    en.wikipedia.org/wiki/Protocol_(science)

    In natural and social science research, a protocol is most commonly a predefined procedural method in the design and implementation of an experiment.Protocols are written whenever it is desirable to standardize a laboratory method to ensure successful replication of results by others in the same laboratory or by other laboratories.

  4. Instrumental variables estimation - Wikipedia

    en.wikipedia.org/wiki/Instrumental_variables...

    One computational method which can be used to calculate IV estimates is two-stage least squares (2SLS or TSLS). In the first stage, each explanatory variable that is an endogenous covariate in the equation of interest is regressed on all of the exogenous variables in the model, including both exogenous covariates in the equation of interest and ...

  5. Benson group increment theory - Wikipedia

    en.wikipedia.org/wiki/Benson_group_increment_theory

    The second-order approximation accounts for two molecular atoms or structural elements that are within relative proximity to one another (approximately 3–5 ångstroms as proposed in the article). By using a series of disproportionation reactions of symmetrical and asymmetrical framework, Benson and Buss concluded that neighboring atoms within ...

  6. Low-energy electron diffraction - Wikipedia

    en.wikipedia.org/wiki/Low-energy_electron...

    A common method to achieve this is the self-consistent multiple scattering approach. [14] One essential point in this approach is the assumption that the scattering properties of the surface, i.e. of the individual atoms, are known in detail.

  7. Qualitative inorganic analysis - Wikipedia

    en.wikipedia.org/wiki/Qualitative_inorganic_analysis

    Classical qualitative inorganic analysis is a method of analytical chemistry which seeks to find the elemental composition of inorganic compounds.It is mainly focused on detecting ions in an aqueous solution, therefore materials in other forms may need to be brought to this state before using standard methods.

  8. Periodic table - Wikipedia

    en.wikipedia.org/wiki/Periodic_table

    The periodic table, also known as the periodic table of the elements, is an ordered arrangement of the chemical elements into rows ("periods") and columns ("groups"). It is an icon of chemistry and is widely used in physics and other sciences.

  9. Ball-and-stick model - Wikipedia

    en.wikipedia.org/wiki/Ball-and-stick_model

    In chemistry, the ball-and-stick model is a molecular model of a chemical substance which displays both the three-dimensional position of the atoms and the bonds between them. [1] The atoms are typically represented by spheres , connected by rods which represent the bonds.