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  2. Reversed-phase chromatography - Wikipedia

    en.wikipedia.org/wiki/Reversed-phase_chromatography

    The organic solvent is called also a modifier, since it is added to the aqueous solution in the mobile phase in order to modify the polarity of the mobile phase. Water is the most polar solvent in the reversed phase mobile phase; therefore, lowering the polarity of the mobile phase by adding modifiers enhances its elution strength.

  3. Lithium hexafluorophosphate - Wikipedia

    en.wikipedia.org/wiki/Lithium_hexafluorophosphate

    The main use of LiPF 6 is in commercial secondary batteries, an application that exploits its high solubility in polar aprotic solvents.Specifically, solutions of lithium hexafluorophosphate in carbonate blends of ethylene carbonate, dimethyl carbonate, diethyl carbonate and/or ethyl methyl carbonate, with a small amount of one or many additives such as fluoroethylene carbonate and vinylene ...

  4. Optical rotation - Wikipedia

    en.wikipedia.org/wiki/Optical_rotation

    The phase velocity of light in a medium is commonly expressed using the index of refraction n, defined as the speed of light (in free space) divided by its speed in the medium. The difference in the refractive indices between the two circular polarizations quantifies the strength of the circular birefringence (polarization rotation),

  5. Lithium aluminium germanium phosphate - Wikipedia

    en.wikipedia.org/wiki/Lithium_aluminium...

    Although Ge 4+ and Al 3+ cations have very similar ionic radii (0.53 Å for Ge 4+ vs. 0.535 Å for Al 3+ [6]), cationic substitution leads to compositional disorder and promotes the incorporation of a larger amount of lithium ions to achieve electrical neutrality. [3] Additional lithium ions can be incorporated in either Li(2) or Li(3) empty ...

  6. Umpolung - Wikipedia

    en.wikipedia.org/wiki/Umpolung

    In organic chemistry, umpolung (German: [ˈʔʊmˌpoːlʊŋ]) or polarity inversion is the chemical modification of a functional group with the aim of the reversal of polarity of that group. [ 1 ] [ 2 ] This modification allows secondary reactions of this functional group that would otherwise not be possible. [ 3 ]

  7. Chemical polarity - Wikipedia

    en.wikipedia.org/wiki/Chemical_polarity

    In chemistry, polarity is a separation of electric charge leading to a molecule or its chemical groups having an electric dipole moment, with a negatively charged end and a positively charged end. Polar molecules must contain one or more polar bonds due to a difference in electronegativity between the bonded atoms.

  8. What does a faint line on a rapid COVID-19 test mean? - AOL

    www.aol.com/faint-line-covid-19-test-225851470.html

    The only situation in which you wouldn't assume that a faint line on a rapid test is positive is if it turned positive after the allotted testing period, Garner says. "If you just left the test ...

  9. Pockels effect - Wikipedia

    en.wikipedia.org/wiki/Pockels_effect

    The Pockels effect occurs in crystals that lack inversion symmetry, such as monopotassium phosphate (KH 2 PO 4, abbr. KDP), potassium dideuterium phosphate (KD 2 PO 4, abbr. KD*P or DKDP), lithium niobate (LiNbO 3), beta-barium borate (BBO), barium titanate (BTO) and in other non-centrosymmetric media such as electric-field poled polymers or ...