# Q. 1.13 Explain how much portion of an atom located at            (i) corner and            (ii) bodycentre of a cubic unit cell is part of its neighbouring unit cell.

(i) At corner:-    Each atom at a corner is shared between eight adjacent unit cells, four unit cells in the same layer and four unit cells of the upper (or lower) layer. Therefore, only $\frac{1}{8}th$of an atom (or molecule or ion) actually belongs to a particular unit cell.