Chapter 12 The Solid State - Study Questions - Page 467c: 43

$N_A=6.0226\times10^{23}$

Volume: $(5.46295\times10^{-8}\ cm)^3=1.6304\times10^{-22}\ cm^3$ Mass: $3.1805\ g/cm^3\times 1.6304\times10^{-22}\ cm^3=5.185\times10^{-22}\ g$ $5.185\times10^{-22}\ g=(4\times40.078+8\times18.998)\ g/mol\div N_A$ $N_A=6.0226\times10^{23}$