The ability of a substance to assume two or more crystalline structures is called

Among the following,which crystal will be soft and have a low melting point?

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?

Graphite and Cinnabar are examples of $.......$ and $.......$ crystal systems,respectively.

Give examples of crystalline solids and polycrystalline solids.

Which of the following is not a characteristic of a crystalline solid?