If X is a non-metal. It will conduct electricity unless it is carbon in the form of: A- Graphite B- Diamond C- Fullerene D- None of these
Hint: We know that the movement of electrons is required for the conduction of electricity. Because moving charges produce electricity. Try to find in which form carbon has most loosely held electrons. That form will conduct electricity.
Complete answer: We know that carbon has many allotropic forms which have different physical and chemical properties. For electrical conductivity, through any substance, we require movement of electrically charged particles. In any substance either there will be no charged particles or there will be electrons as charged particles that can move. Due to the movement of electrons some substances conduct electricity. From the options, we can find which will be the conductor of electricity. Graphite form is an easily available form of carbon that has many uses. In graphite, each carbon atom is joined to 3 other carbon atoms. There will be a carbon-carbon double bond in this form. Due to the delocalization of these pi-electron clouds present all over the substance graphite is a very good conductor of electricity. Diamond is the hardest mineral on the earth. In diamond, each carbon atom is connected to 4 other carbon atoms. There will be no pi bonds in this allotrope. Movement of sigma bond electrons will be very less as a result it is not a good conductor of electricity. Fullerenes are also allotropes of carbon. Fullerenes consist of some single bonds and some double bonds. Fullerenes normally do not conduct electricity but when used with some other metals they can be good conductors. Therefore, among carbon allotropes, graphite is the best conductor of electricity.
So, the correct answer is “Option A”.
Note: Every substance is a conductor of electricity but some substances have a negligible amount of conductivity such substances are called insulators. The vacuum has no charged particles so the vacuum is the best insulator.