notesonly.in

Compare surface-to-volume ratio of a 1 cm cube vs 1 nm cube (same material). Cube: S/V = 6/a. For a = 1 cm: 6 cm⁻¹. For a = 1 nm = 10⁻⁷ cm: 6×10⁷ cm⁻¹. The nanocube has 10 million times more surface per volume — that's why nanocatalysts are so reactive.