Assertion: Anion vacancies in alkali halides are produced by heating the alkali halide crystals with alkali metal vapour. Reason: Electrons trapped in anion vacancies are referred to as F -centres.A. If both assertion and reason are true and the reason is the correct explanantion of the assertionB. If both assertion and reason are true but reason is not the correct explanation of the assertion.C. If assertion is true but reason is false.D. If the assertion and reason both are false.

Assertion: Anion vacancies in alkali halides are produced by heating t

1.	Assertion: Anion vacancies in alkali halides are produced by heating the alkali halide crystals with alkali metal vapour. Reason: Electrons trapped in anion vacancies are referred to as F -centres.A. If both assertion and reason are true and the reason is the correct explanantion of the assertionB. If both assertion and reason are true but reason is not the correct explanation of the assertion.C. If assertion is true but reason is false.D. If the assertion and reason both are false.
Answer» Correct Answer - B On heating , the metal atoms deposit on the surface and finally they deffuse into the crystal and after ionisation the alkali metal ion occupies cationic vacancy where as electron occupies anionic vacancy.

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