Examine the given defective crystal :

Answer the following questions :
(i) Is the above defect stoichiometric or non-stoichiometric ?
(ii) Write the term used for this type of defect. Give an example of the compound which shows this type of defect.
(iii) How does this defect affect the density of the crystal ?

Explanation

(i) It is stoichiometric defect.
(ii) Schottky defect.eg NaCl and Kcl
(iii) Like simple vacaney defect, Schottky defect also decreases the density of the substance. Number of such defects in ionic solids in quite significant.