Is it in an atom only electrons can be moved from place to place?

Electrons, which are usually associated with the positive nuclei of atoms, can occasionally jump up or down in their orbitals, or participate in numerous forms bonding with other atoms, which requires their re-positioning; a common model for good conductors such as metals describes nuclei in fixed positions with valence electrons around them somewhat like a "sea" and not necessarily associated with any specific atom - thus free to move and thus create a current when an electromotive force is applied.

Electrons are also located away from atoms, usually then termed 'dissociated' - nuclei may emit them as a form of ionizing radiation in beta decay; they may be removed by heat, radiation, or other effects; electrons are a component of cosmic rays, freely moving high energy particles in space, although they represent only a small fraction of particles which make up cosmic radiation.