Explain paramagnetism and paramagnetic substances.

(N/A) Paramagnetic substances are those which get weakly magnetized when placed in an external magnetic field. They have a tendency to move from a region of weak magnetic field to a strong magnetic field,meaning they get weakly attracted to a magnet.
The individual atoms (or ions or molecules) of a paramagnetic material possess a permanent magnetic dipole moment of their own.
On account of the ceaseless random thermal motion of the atoms,no net magnetization is seen in the absence of an external field.
In the presence of an external field,the dipole moments of a paramagnetic substance can be made to align in the same direction as the field.
The value of magnetic susceptibility $\chi$ for these substances is positive.
If a paramagnetic material is placed in an external field,the field lines get concentrated inside the material and the field inside is enhanced.
This enhancement is slight,being one part in $10^{5}$.
When a bar of the substance is placed in a non-uniform magnetic field,the bar will tend to move from a weak field to a strong field.
Some examples of paramagnetic materials are aluminum,sodium,calcium,oxygen (at $STP$),and copper chloride.