What is an element which is a solid, dull in appearance, very brittle, and conducts electricity?

Elemental carbon is a black, dull-looking solid that conducts heat and electricity well. It is very brittle and cannot be made into thin sheets or long wires. Of these properties, how does carbon behave as a metal? How does carbon behave as a nonmetal? Pure silicon is shiny and silvery but does not conduct electricity or heat well.

Explanation:

nacl is added to the aqueous of what? ? in order to get a proper answer you have to specify the exact composition of the aqueous solution.