Atomic Dipole Moment is the key to understand many basic physics phenomenon……specially those cases where one study the materials, molecule or atoms in the presence of the external magnetic field. How the magnetic field interact with the atoms, or molecules ?
In this video the main purpose is to make the idea more clear about the contribution of orbital and spin motion of the electron and further the contribution of the orbital angular and spin angular momentum for the dipole moment.
What is atomic magnetic dipole moment? and how atom can behave like a bar magnet? and as you know that when a permanent bar magnet is placed in a uniform magnetic field, how a torque works on the bar magnet and as a result the moment in magnetic dipole. All these basic ideas are generalized here for the atoms and explained some phenomena of physics on its basis like for an example susceptibility. In which Intensity of magnetization of the substance plays the role, further this intensity of magnetization depends on the atomic dipole moments which is defined as the magnetic dipole moment per uni volume. So it means if one knows about the atomic dipole he/she can understand such phenomena otherwise not possible to understand the concept of magnetic susceptibility, or like this other topics as Zeeman Effect.