Calculate the density of an element having molar mass $$27 \mathrm{~g} \mathrm{~mol}^{-1}$$ that forms fcc unit cell. $$\left[\mathrm{a}^3 \cdot \mathrm{N}_{\mathrm{A}}=38.5 \mathrm{~cm}^3 \mathrm{~mol}^{-1}\right]$$

What type of following solids the ice is

Calculate the edge length of simple cubic unit cell if radius of an atom is $$167.3 \mathrm{~pm}$$.

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