Refer section 11.1.1 of your NCERT. What peculiarity does NCERT mention regarding diffusion and solids ?
1. It does not occur in solids
2. It is more easily visualized in solids
3. It requires expenditure of external energy and occurs against concentration gradient
4. Diffusion in solids rather than of solids is more likely.
Prefer Books for Question Practice? Get NEETprep's Unique MCQ Books with Online Audio/Video/Text Solutions via Telegram Bot
NEET MCQ Books for XIth & XIIth Physics, Chemistry & Biology