D

A dihedral angle is obtained when two planes pass through three atoms and two bonds, of which one bond is common to both planes. 

In the below example, plane 1 passes through X-C-C, containing three atoms and two bonds. Similarly, the plane 2 passes through C-C-Y. The separation between the two planes or the angle of intersection is denoted using a dihedral angle (ϴ) in degrees (^o).

The redistribution of electrons in an atom, bond, or molecule creates two ends (or poles), one electron-rich negative and the other electron-deficient positive; such an atom, bond, or molecule is said to have a dipole (two poles).

Dialysis is a process of diffusion of the colloidal particles through a parchment or an animal membrane to remove excess of an electrolyte or any soluble impurities (crystalloids).