Question

why atoms of magnet differ from normal atoms?​

Answer 1

In an atom, magnetism arises from the spin and orbital momentum of its electrons. 'Magnetic anisotropy' describes how an atom's magnetic properties depend on the orientation of the electrons' orbits relative to the structure of a material. It also provides directionality and stability to magnetization.

Answer 2

$\huge\mathsf\blue{Answer}$

The magnetic field of an atom, say H (one electron revolving around a proton) is composed of two separate contributions: an orbital magnetic moment and a spin magnetic moment. We get magnetic moments because of electromagnetic induction associated with each type of electron motion. The electron revolving around the proton with a certain angular momentum is related to the associated orbital magnetic moment (and, yes, we model it as a wire loop with current expressed in terms of the orbital velocity). This can be calculated using elementary mechanics. The spin magnetic moment is a little trickier because it is caused by the intrinsic spin of the electron which is a quantum phenomenon; therefore, this spin magnetic moment can only be calculated using quantum mechanics