A metal crystallises in bcc lattice with unit cell edge length of $$300 \mathrm{~pm}$$ and density $$615 \mathrm{~g~cm}^{-3}$$. The molar mass of the metal is

A metal crystallises in face centred cubic structure with metallic radius $$\sqrt{2} \mathop A\limits^o$$. The volume of the unit cell (in $$\mathrm{m}^3$$ ) is

Silicon doped with gallium forms

Which of the following is a network crystalline solid?