Question

9. Surface layer of solid means 1) atoms present in the upper layer of the solid. 2) atoms present upto a depth of 100 nm on the surface. 3) atoms present in the bulk of the solid. 4) atoms of surface of solid not preoccupied by other substances.

Answer 1

Answer:

2

Explanation:

Its answer is 2

surface layer of solid means atoms present up to a depth of 100 nm