atomic dielectric material
The nuclear is at the centre, and the various elections revolving around it can be thought of as a spiritual symmetrically cloud of elections.For points outside the atom this cloud of electrons can be regarded as concentrated at the centre of the atom has a point charge.
the most of the atoms and molecules, d centuries of positive and negative charge inside with each other, whereas, In some molecule the centre of the two charge are located at different point such molecule are called polar molecule.
further, we note that in the electric, all the electrons are firmly bond to their respective atom and are unable to move about freely. in the absence of an electric field, they charge inside the molecule atoms are there equilibrium position. the arrangement of the molecules in a dielectric material is shown below
discharge centre as shown coincident as the centre of sphere. keeping this picture of a dielectric in mind you will no and predict the behaviour of dielectric in an electric field.