When a dielectric material is placed in an electric field, what occurs at the molecular level that contributes to its polarization?

When a dielectric is put in an electric field, the field pulls on the charges inside each molecule, causing the positive and negative parts of the molecule to shift slightly. This shift creates tiny dipoles that point in the direction of the field, so the material as a whole becomes polarized. The induced dipoles add a field that opposes the original external field, reducing the overall electric field inside the material. For example, in water, the electric field makes the oxygen end slightly negative and the hydrogen ends slightly positive, aligning the molecules and creating a net dipole moment. The result is a reduced electric field inside the dielectric and an increased capacitance of any capacitor that contains it.