Answer
$\rho=5.07\frac{g}{cm^3}$
Work Step by Step
Given raidus=0.145 nm,Atomic weight=74.5g\mol, and
$\rho=\frac{nA}{{V_{c}}{N_{A}}}$
For SC, n=1 and $V_{c}=(2r)^3$
$N_{A}=6.023\times10^{23} \frac{atom}{mol}$ is Avogadro's number.
$\rho=\frac{74.5}{{0.145}^3\times6.023\times10^{23}}$
$\rho=5.07\frac{g}{cm^3}$
