5. The ratio of number of atoms or number of cations and
anions of compounds remains the same as represented by its
chemical formula
i) Vacancy Defect :
6. ii) Self interstitial Defect in elemental solid :
Density increases
Extra particle occupies an empty space in crystal lattice
7. A particle gets shifted from its original lattice point and occupies an
interstitial space in crystal.
Density doesn’t change.
ii) Self interstitial Defect in elemental solid :
10. Difference between Schottky and frenkel defect
Schottky defect frenkel defect
Occurs in those ionic crystals where
difference in size between cation and anion
is small.
Occurs in those ionic crystals where size of
anion is quite large as compared to that of
the cation.
Ions have high coordination number Ions have low coordination number
Both cation and anion leave the solid
crystal.
Only the smaller ion (cation) leaves its
original lattice site; whereas, the anion
remains in original lattice sites.
Two atoms reduce from the crystal for
each hence schottky defect reduces density
of the solid.
The number of atoms present in the crystal
before and after defect remains same,
hence density of the solid remains same
e.g. NaCl, KCl, AgBr e.g. ZnS, AgCl
11. Foreign atoms are present in the crystal lattice.
i) Substitutional Impurity Defect
Solid solutions of metals Vacancy thruogh aliovalent impurity
13. The ratio of number of atoms or number of cations and anions of
compounds become different from that indicated by its chemical
formula
i) Metal deficiency Defect
14.
15. ii) Metal excess Defect
Defect due to extra positive charge occupying interstitial position