Figure 2. EDX spectra (a), elemental composition (b) and SEM image (c) of mechanically scrubbed copper surface

From

Copper Dissoliution in Concentrated Sulfuric Acid

A. Sulcius, E. Griskonis, N. Zmuidzinaviciene

World Journal of Chemical Education. 2019, 7(3), 196-202 doi:10.12691/wjce-7-3-2