question_answer 119)

      Assertion (A) The total number of atoms present in a simple cubic unit cell is one. Reason (R) Simple cubic unit cell has atoms at its corners, each of which is shared between eight adjacent unit cells.  

Answer:

                  (a) In simple cubic unit cell each atom is present at corners having contribution 1/8. Hence, total number of atoms present per unit cell in sec is  x 8 = 1.