Question

Which of the following non-metal is a good conductor of electricity?
A. Graphite
B. Hydrogen
C. Phosphorous
D. Bromine

Answer 1

Hint: It is an allotrope of a group 14 element. The other allotrope of it is a bad conductor of electricity.

Complete step by step answer:
The non-metal which is a good conductor of electricity is Graphite. It is an allotrope of carbon. In graphite, one valence electron of each carbon atom is free. Graphite is fully composed of layers of graphene, which has the highest electrical conductivity. If we look at the bonding of graphene, each carbon atom is \[s{p^2}\] hybridized.
Each carbon atom makes three bonds with other three carbon atoms by sigma bond. Hence, each carbon atom has one free pi electron which is delocalised. This free electron acts as an electron cloud above and below the graphene layer. Therefore, the whole graphene layer can be considered as a sea of electrons with carbon atoms submerged in it.
Graphite has a layered hexagonal arrangement. The other allotrope of carbon is Diamond, which is a bad conductor of electricity. This is because diamond has no free valence electrons to conduct electricity. Each carbon atom makes four bonds in diamond, thus leaving no free electron. Diamond has a crystal structure with a face centered cubic Bravais lattice.
So, the correct option is A.

Note: As graphite is a good conductor of electricity, a student can consider carbon to be a good conductor of electricity, which is not the case. In reality, it is not carbon which conducts the electricity but the free electron of carbon present in graphite is responsible for conducting.