## Chemistry and Chemical Reactivity (9th Edition)

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: $1.91\times10^{15}\times 3.14\times10^{-10}\ cm^2 = 6.0\times10^5\ cm^2=60\ m^2$