Which of the following elements has a simple cubic lattice structure in its solid state?

Why does the electrical conductivity of semiconductors increase with a rise in temperature?

Crystalline sodium chloride is an insulator of electricity because...

Which of the following is a network crystalline solid?

Solid $A$ is a very hard electrical insulator in solid as well as in molten state and melts at extremely high temperature. What type of solid is it?

$A$ solid is hard and brittle. It is an insulator in solid state,but conducts electricity in molten state. The solid is a