Why iron in our body does not attracted by magnet
Answers
Iron in your body is not ferromagnetic. The strong attraction of iron to a magnet is due to ferromagnetism. This is magnetism in the colloquial sense. Ferromagnetism occurs in some materials which have molecules with a permanent magnetic dipole moment. When the material is placed in a magnetic field, molecules with a magnetic dipole moment tend to line up with the external magnetic field. In addition to this, ferromagnetic molecules also interact very strongly with one another (the exchange interaction: a quantum mechanical interaction in which the orbital motion of electrons from separate atoms are coupled), and this causes much more alignment with the external magnetic field. The interaction between molecules is strong enough for domains of aligned molecules to form, even when no external magnetic field is present. In an external magnetic field, the domains of molecules become partially aligned, producing an overall magnetisation in the material. If this material was a red blood cell, you might expect a magnet to attract or orient the red blood cell. However, the exchange interaction which causes ferromagnetism does not occur unless iron is found in bulk form. In the body, iron is distributed in various chemical compounds such as haemoglobin (in red blood cells), serum ferritin (iron stores) and haemosiderin (e.g. in clotted blood). These compounds are not ferromagnetic; they are weakly paramagnetic.