Schottky defect is observed in crystals when ……………. .

Options

A. some cations move from their lattice site to intersititial sites
B. equal number of cations and anions are missing form the lattice
C. some lattice sites are occupied by electrons
D. some impurity is present in the lattice

Answer

B

Explanation

Scottky defect is observed in crystal when equal number of cations and anions are missing from the lattice thus , density of solid decreases.
when some cations move from their lattice site to intersititial site is known as feenkel defect , when some impurity is present on crystal is known as impurity defect .
when lattice site is occupied by eletron , this type of defect is known as metal excess defect Hence except (b) all statement are incorrect regarding schottky defect .