Graphite, an allotrope of carbon, is often used as an electrode in dry cells, even though carbon is classified as a non-metal. What unique property of graphite allows it to be used for this purpose, unlike most other non-metals?
Options
It is very hard.
It is shiny and lustrous.
It is a good conductor of electricity.
It is highly reactive with acids.
Explanation
Most non-metals are poor conductors of electricity, acting as insulators. However, graphite is a unique allotrope of carbon that is an excellent conductor of electricity. This exceptional property, due to its specific crystalline structure where delocalized electrons are present, makes it suitable for use as an electrode in various electrochemical devices like dry cells. Its hardness is not its key property for this use (diamond is hard), nor is its slight lustre. Non-metals are generally unreactive with acids, so high reactivity is not a factor.