2. Explain how much part of atom present at (1) corner and (2) centre of cubic unit cell is divided between nearby cell?

Dear Student,

Each atom is surrounded by 8 atoms. Thus each corner is shared by 8 atoms. The contribution given by one corner to the atom is 1/8. the atom located at the centre of the cube is not shared by neighbouring atoms. Thus its contribution is 1.
Therefore the no. of atoms in BCC is 2.

Regards,