Question

why................??

Answer 1

Answer:

Schottky defect - This type of defect is typically observed in highly ionic compounds, highly coordinated compounds, and where there is only a small difference in sizes of cations and anions of which the compound lattice is composed. Typical salts where Schottky disorder is observed are NaCl, KCl, KBr, CsCl and AgBr.

Answer 2

Explanation:

Frenkel defect

A stoichiometric or interstitial defect, arises when the smaller ion i.e. cation is dissociated from it's normal site to an interstitial site.

It results increase in conductivity but density of the crystal remains the same.

Schottky defects

A stoichiometric or vacancy defect, arises due to missing of equal number of cations and anions from the lattice and is shown by crystals having cation and anion of comparable size.

Example - CsCl, NaCl, AgBr

It results a decrease in density.