Magnetic Moments of Atoms and Molecules

The discussion of ionization energies of atoms will be continued in Section 6-9. 

A sample of a diamagnetic substance placed in an inhomogeneous magnetic field is acted on by a force that tends to push it into the region where the field is weaker. A sample of paramagnetic substance is pulled into the stronger field. 

The explanation of diamagnetism is that the application of a magnetic field induces a motion of the electrons in an atom or monatomic ion in a direction such as to give rise to a magnetic dipole with orientation opposed to the field. All substances show this diamagnetic efifect. 

The magnetic susceptibility of a diamagnetic or paramagnetic substance is defined by the equation 

It was shown by Pierre Curie in 1895 that paramagnetic susceptibility is strongly dependent on temperature, and for many substances is inversely proportional to the absolute temperature. The equation 

---