Molecular Polarity

Molecular polarity is the extent to which the electron density within a molecule is not symmetric, which results in the electron density accumulating toward one side of the molecule, giving that side a partial negative charge, and leaving the other side with a partial positive charge.  The molecule's dipole moment is defined as the product of the magnitude of the partial charges and the distance by which they are separated.  In order to predict whether or not a molecule is polar, one must consider if the molecule has polar bonds and how these bonds are positioned relative to one another.
This module simulates the changes of a molecule's overall polarity as a function of the different atoms in the molecule, their electronegativities and the shape of the molecule.  Electronegativity values for the available atoms are listed.
 
 
 

 

      INSTRUCTIONS:
 

• The first two molecules displayed are BF₃, a trigonal planar molecule and the BeF₂ molecule which is a linear molecule. To change any atom, click on the atom and then choose a different atom from the appropriate menu as its replacement. If the molecule is polar, an arrow indicates the direction of the resultant dipole.