A sports medal has a total surface area of 150 cm^2. It was evenly coated with silver by
electrolysis. Its mass increased by 0.216g. How many atoms of silver were deposited per cm^2 on the surface of the medal?
A. 8.0 × 10^18
B. 1.8 × 10^19
C. 8.7 × 10^20
D. 1.2 × 10^21
