Question

which of the following is non ductile
silver
gold
copper
carbon

Answer 1

carbon is non ductile

Answer 2

Carbon is non ductile because it is an insulator which does not conducts electricity.

An insulator or a conductor depends on the conductance resistance present in the particle or the substance which results in flow of electrons through it. Ductility depends on whether the objects conducts electricity and heat conductivity depends on the same criteria for electrical conductivity.