Answer
See the answer below.
Work Step by Step
a) Radius: $0.5\times10^2\ nm=0.5\times10^{-5}\ cm$
Volume: $4\pi/3\times r^3=5.24\times10^{-16}\ cm^3$
Surface area: $4\pi\times r^2=3.14\times10^{-10}\ cm^2$
b) 1.0 $cm^3$ total volume: $1.0\ cm^3\div5.24\times10^{-16}\ cm^3=1.91\times10^{15}$
Surface area of this many spheres: $1.91\times10^{15}\times 3.14\times10^{-10}\ cm^2 = 6.0\times10^5\ cm^2=60\ m^2$
