Full Charges | Partial Charges | Transient Charges |
---|---|---|
Atoms attain full charges (+ or -) by losing or gaining electrons and forming ions. So, a full charge on an ion is equivalent to the charge of a proton (in case of electron loss) or an electron (in case of electron gain).
| When some atoms form a covalent bond, the electrons in the bond tend to reside closer to one atom than the other. This creates a shift in the electron density of the bond, which is represented by the delta δ sign. The atom with more electron density is assigned δ-, while the atom with less electron density is assigned δ+. This separation of charges creates dipoles or opposite poles in covalently bonded molecules.
| Atoms or covalently bonded nonpolar molecules attain transient charges due to the constantly fluctuating position of electrons. At a given moment, the electron density is higher on one end, creating a temporary negative pole while the other is the positive pole. This induces dipole formation in nearby nonpolar molecules so that they reorganize and reorient according to their poles and show intermolecular (or interatomic) attraction. |
Atoms forming ionic bonds usually attain full charges.
| Atoms forming covalent bonds and having electronegativity differences between them in the range of 0.5 to 1.7 are assigned partial charges. | Transient charges are developed in inert atoms or covalent molecules where the electronegativity difference between atoms is 0 to 0.4. |
Such ions carrying full charges show the highest electrostatic attraction with their opposite counterpart.
| The electrostatic attraction between molecules is weaker than that between ions, as it depends on the magnitude of the charges and their distance. Ions have a higher magnitude of charge than partial charges. | The electrostatic attraction between molecules carrying transient charges is weakest since the charges are temporary. |
The formation of ions that carry integer charges (not zero) depends on the ionization enthalpy and electron affinity values of the atoms. | The electronegativity of an atom causes partial charges to develop, which leads to the formation of dipoles. | Electron motion causes every atom or molecule to develop transient charges. London Dispersion force, a subtype of Van der Waal force, is an example of intermolecular attraction due to transient charges. |
Examples: Na+, Cl-, Mg2+, O2-. | Examples: Hδ+-Clδ- (HCl), H δ+-O2δ--Hδ+ (H2O) | Examples: He, H2. |
Note: Full, partial, and transient charges are different from formal charges.
Related Reading- Bonding in Atoms (Ionic bond and Covalent Bond), Intermolecular Force (Vander Waals- London, Debye, and Keesom).