Question

$F-$centres are :

• A. the electrons trapped in anionic vacancies
• B. the electron trapped in cationic vacancies
• C. non-equivalent sites of stoichiometric compound
• D. All of the above

Answer 1

The correct option is A the electrons trapped in anionic vacancies

$F$-centres or colour centres are points in a crystalline compound at which negative ion missing is replaced by one or more unpaired electrons.

Hence, they are electrons trapped in anionic vacancies.

Therefore, the option is A.