enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Formal charge - Wikipedia

    en.wikipedia.org/wiki/Formal_charge

    Formal charges in ozone and the nitrate anion. In chemistry, a formal charge (F.C. or q*), in the covalent view of chemical bonding, is the hypothetical charge assigned to an atom in a molecule, assuming that electrons in all chemical bonds are shared equally between atoms, regardless of relative electronegativity.

  3. Abegg's rule - Wikipedia

    en.wikipedia.org/wiki/Abegg's_rule

    In chemistry, Abegg's rule states that the difference between the maximum positive and negative valence of an element is frequently eight. The rule used a historic meaning of valence which resembles the modern concept of oxidation state in which an atom is an electron donor or receiver. Abegg's rule is sometimes referred to as "Abegg’s law of ...

  4. Goldman equation - Wikipedia

    en.wikipedia.org/wiki/Goldman_equation

    Since the valence has already been accounted for above, the charge q A of each ion in the equation above, therefore, should be interpreted as +1 or -1 depending on the polarity of the ion. There is such a current associated with every type of ion that can cross the membrane; this is because each type of ion would require a distinct membrane ...

  5. Effective nuclear charge - Wikipedia

    en.wikipedia.org/wiki/Effective_nuclear_charge

    In atomic physics, the effective nuclear charge of an electron in a multi-electron atom or ion is the number of elementary charges an electron experiences by the nucleus. It is denoted by Z eff . The term "effective" is used because the shielding effect of negatively charged electrons prevent higher energy electrons from experiencing the full ...

  6. Hammett equation - Wikipedia

    en.wikipedia.org/wiki/Hammett_equation

    0<ρ<1, the reaction is less sensitive to substituents than benzoic acid and negative charge is built (or positive charge is lost). ρ=0, no sensitivity to substituents, and no charge is built or lost. ρ<0, the reaction builds positive charge (or loses negative charge). These relations can be exploited to elucidate the mechanism of a reaction.

  7. Charge number - Wikipedia

    en.wikipedia.org/wiki/Charge_number

    An element's placement on the periodic table indicates whether its chemical charge is negative or positive. Looking at the table, one can see that the positive charges are on the left side of the table and the negative charges are on the right side of the table. Charges that are positive are called cations. Charges that are negative are called ...

  8. Charge carrier - Wikipedia

    en.wikipedia.org/wiki/Charge_carrier

    There are two recognized types of charge carriers in semiconductors.One is electrons, which carry a negative electric charge.In addition, it is convenient to treat the traveling vacancies in the valence band electron population as a second type of charge carrier, which carry a positive charge equal in magnitude to that of an electron.

  9. Chemical polarity - Wikipedia

    en.wikipedia.org/wiki/Chemical_polarity

    Two charges are present with a negative charge in the middle (red shade), and a positive charge at the ends (blue shade). 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.