Which one of the following is a molecular crystal?

Crystalline metal can be transformed into metallic glass by

Which among the following metals crystallises as a simple cube?

What type of semiconductor is obtained by doping $Si$ with $B$ $(Al, Ga)$?

Explain why the conductivity of germanium crystals increases on doping with gallium.

$A$ solid which is very hard,has a very high melting point in the solid state,is an insulator,and becomes a conductor of electricity in its molten state is a/an ..... solid.