NEETChemistrySolid State
What causes the metal excess defect due to anionic vacancies in alkali halides like NaCl and KCl?
Options
- ALoss of electrons by Cl⁻ ions
- BDeposition of sodium atoms on the crystal surface
- CDiffusion of Cl⁻ ions to the crystal surface
- DFormation of Cl₂ molecules
Correct answer
B. Deposition of sodium atoms on the crystal surface
Step-by-step solution
In the metal excess defect due to anionic vacancies, sodium atoms are deposited on the surface of the crystal, and Cl⁻ ions diffuse to the surface and combine with Na atoms.