Answer
The density of galena is 7.56 $\frac{g}{cm^{3}}$
Work Step by Step
1- Density is the mass per unit of volume. In formula: d= $\frac{m}{v}$
2-We know the mass of the sample is 12.4 while the volume is 1.64 $cm^{3}$.
3- Replace the value of mass and volume in formula of density:
d= $\frac{12.4 g }{1.64 cm^{3}}$
4- We calculate the density of galena 7.56 g/ $cm^{3}$
