What are the number of octahedral and tetrahedral voids in 0.3 mole substance respectively if it forms hcp structure?

Calculate the molar mass of an element having density $$7.8 \mathrm{~g} \mathrm{~cm}^{-3}$$ that forms bcc unit cell. $$\left[\mathrm{a}^3 \cdot \mathrm{N}_{\mathrm{A}}=16.2 \mathrm{~cm}^3 \mathrm{~mol}^{-1}\right]$$

Identify the example of zero-dimensional nanostructure from following.

Identify the good conductor of electricity from following band gap energy values of solids.