Which of the following is a molecular crystal?

$A$ clock spring is heated to redness and then plunged into cold water. This treatment will cause it to become

Which of the following is a pseudo solid?

Classify the following materials into superconductors,conductors,semiconductors,and insulators: $Cu$,$Al$,$Si$,$Ge$,glass,Teflon,$Au$,$Pt$,$CuO$ (at low temperature),graphite,carbon black,and alloys at low temperature.

Pure silicon doped with phosphorus is

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?