A general STM constant current topography (250nm X 250nm) of 4 atomic layer metallic silver films is shown in appended figure-1. Determine the average thickness (in unit) of each atomic layer. Interpret why several ascorbates (white marks) on the surface mostly located at the step edge? You may use any image processing platform like Matlab, imag J etc.

1.12 nm 50nm 0.00 mm 50nm 1.12 nm 50nm 0.00 mm 50nm