Question

cubic close packing (CCP) is ABC ABC type packing. the maximum number of atom present in one plane of this packing which are in contact with one atom are​

Answer 1

The maximum no of atom is 4 .

Explanation :

• Cubic close packing or CCP is similar to FCC , so it has lattice points at the eight corners of the unit cell and also at the centre of each face of the unit cell .
• Since every atom at corners contribute $\frac{1}{8}$ to the cell .
• And atom at face centre contributes $\frac{1}{2}$ to the unit cell .
• So, the no of atoms in a unit cell is =$(8 \times \frac{1}{8} + 6 \times \frac{1}{2}) = 4$ atoms

Hence in CCP type packing , the maximum no of atoms in one  plane which  are in contact with one atom is equal to 4 .