Induced electric dipoles

Definition

Induced electric dipoles occur when an external electric field causes a redistribution of charges within an atom or a molecule, leading to a temporary separation of positive and negative charges. This phenomenon results in a dipole moment that aligns with the external field, allowing the atom or molecule to interact with the field and other charged entities. Induced dipoles play a crucial role in various physical processes, including intermolecular interactions and polarization effects.

5 Must Know Facts For Your Next Test

1. Induced electric dipoles are temporary and disappear when the external electric field is removed.
2. The strength of the induced dipole is directly proportional to the strength of the applied electric field.
3. Nonpolar molecules can still exhibit induced dipoles when exposed to an external electric field, leading to temporary interactions with polar molecules.
4. Induced dipoles contribute to London dispersion forces, which are weak intermolecular forces important in the behavior of nonpolar substances.
5. In dielectric materials, the presence of induced dipoles enhances their ability to store electric energy when subjected to an external field.

Review Questions

• How do induced electric dipoles form when an external electric field is applied, and what factors affect their strength?
  • Induced electric dipoles form when an external electric field causes a redistribution of electrons in an atom or molecule, leading to a temporary charge separation. The strength of the induced dipole depends on the magnitude of the external electric field and the polarizability of the atom or molecule, which measures how easily its electron cloud can be distorted. Larger atoms with more electrons typically have higher polarizability, resulting in stronger induced dipoles.
• Compare and contrast induced electric dipoles with permanent electric dipoles in terms of their formation and characteristics.
  • Induced electric dipoles arise from an external electric field causing charge redistribution within neutral atoms or nonpolar molecules, whereas permanent electric dipoles exist due to fixed charge separations in polar molecules. Induced dipoles are temporary and only present while the external field is applied, while permanent dipoles maintain their separation regardless of external conditions. This distinction influences how these dipoles interact with each other and with external fields, impacting molecular behavior in different scenarios.
• Evaluate the role of induced electric dipoles in intermolecular forces and their implications for material properties.
  • Induced electric dipoles significantly impact intermolecular forces, particularly through London dispersion forces that occur even among nonpolar molecules. These induced interactions contribute to properties such as boiling points and solubility in various materials. For instance, substances with higher polarizability can exhibit stronger dispersion forces, leading to higher boiling points compared to less polarizable counterparts. Understanding these interactions helps explain the behaviors of gases, liquids, and solids under varying conditions.

Related terms

Permanent electric dipoles: Permanent electric dipoles are molecules that have a fixed separation of positive and negative charges due to their molecular structure, resulting in a constant dipole moment.

Polarization: Polarization is the process by which the distribution of electric charge within a material is distorted in response to an external electric field, creating induced dipoles.

Dipole moment: The dipole moment is a vector quantity that represents the strength and direction of a dipole, defined as the product of charge magnitude and the distance between the charges.