Give reason:
(i) In stochiometric defects, NaCl exhibits schottky defect and not Frenkel defect.
(ii) Silicon on doping with phosphorus forms n-type semiconductor .
(iii) Ferrimagnetic substances show better magnetisation than antiferromagnetic substences.

Explanation

(i) Schottky defect is shown by those compounds which have small difference in the size of catio and anoin whereas Frenkel defect is shown by those compounds which have large difference in the size of cation and anion. As the difference in the size of `Na^(+) and Cl^(-)` ions is small, hence it shows schoottky defect.
(ii) Silicon belongs to Group 14 whereas phosphorus blongs to Group 15. s phosphorus has one extra electron than silicon, this extra electron makes silicon a semiconductor. Hence, we get n-type semicondutor.
(iii) Ferrimagnetic substances have as unequal number of electrons with spin in the opposite direction. Hence, they have a net magnetic moment. Antiferromagnetic substances have equal number of electrons with spin in the opposite direction. Hence, their net magnetic moment is zero. For this reason, ferrimagnetic subtances show better magnetism tha antiferromagnetic substances.