Face centered cubic lattice of NaCl may also smaller, tetragonal unit cell as shown below fig. (a,b) The number of formula units of NaCl present in smaller unit cell drawn in (b) are

Face centered cubic lattice of NaCl may also smaller, tetragonal unit

1.	Face centered cubic lattice of NaCl may also smaller, tetragonal unit cell as shown below fig. (a,b) The number of formula units of NaCl present in smaller unit cell drawn in (b) are
Answer» 1 2 3 4 Solution :A,UNIT cell (a): the slating unit cell LENGTH is `(l)/sqrt(2)`, where l=length of fcc unit cell. Unit cell (b): the angle between the TWO edges on the front face (HEAVIER LINES) is `90^(@)` . This unit cell extends only `(l)/(2)` towards back, there fore the volume of unit cell `(l)/sqrt(2)xx(l)/sqrt(2)xx(l)/sqrt(2)=(l^(3))/(4)=(v)/(4)`