Before the Discovery of the Element Germanium in 1886, Its

Before the discovery of the element germanium in 1886, its existence was predicted by Mendeleev as "eka-silicon". Mendeleev not only predicted the existence of this element but also its properties. Use the density of the neighboring elements to estimate the density of Ge.

$\begin{array}{|l|l|l|}\hline \text { Element } & \text {Symbol } & \text {Density}\\\hline\\\hline \text { Aluminum } & \text { A1 } & 2.70 \mathrm{~g} \mathrm{~cm}^{-3} \\\hline \text { Silicon } & \mathrm{Si} & 2.33 \mathrm{~g} \mathrm{~cm}^{-3} \\\hline \text { Phosphorous } & \mathrm{P} & 1.82 \mathrm{~g} \mathrm{~cm}^{-3} \\\hline \text { Arseric } & \text { As } & 5.73 \mathrm{~g} \mathrm{~cm}^{-3} \\\hline \text { Tin } & \mathrm{Sn} & 7.30 \mathrm{~g} \mathrm{~cm}^{-3} \\\hline \text { Antimony } & \mathrm{S} \mathrm{b} & 16.70 \mathrm{~g} \mathrm{~cm}^{-3} \\\hline \text { Indium } & \mathrm{In} & 7.30 \mathrm{~g} \mathrm{~cm}^{-3} \\\hline\end{array}$

A) 2.5 g cm^-3
B) 4 g cm^-3
C) 5.5 g cm^-3
D) 7 g cm^-3
E) 9.6 g cm^-3