Which of the following carbon allotropes is/are good conductor(s) of electricity ?
- 1. Diamond
- 2. Graphite
- 3. Fullerene
Select the correct answer using the code given below :
1 only
1 and 2 only
2 only
1 and 3 only
Answer is Right!
Answer is Wrong!
This question was previously asked in
UPSC CDS-2 – 2021
2. Graphite: In graphite, carbon atoms are arranged in layers of hexagonal rings. Within each layer, atoms are covalently bonded (sp2 hybridisation). Each carbon atom has one valence electron that is not involved in sigma bonding and is delocalized across the layers. These delocalized electrons are free to move, making graphite a good conductor of electricity.
3. Fullerene: Fullerenes, such as C60, have carbon atoms arranged in spherical or cage-like structures involving pentagons and hexagons. The bonding is predominantly sp2 hybridisation with some delocalized electrons. However, in their pure form, most fullerenes are semiconductors or insulators due to the localisation of the pi electrons compared to graphite. While some doped fullerenes can become conductors or even superconductors, pure fullerenes are not considered good conductors in the same way as graphite.
Therefore, among the listed common allotropes, only graphite is a good conductor of electricity.
– Diamond has no free electrons.
– Graphite has delocalized pi electrons allowing it to conduct electricity.
– Pure fullerenes are typically semiconductors or insulators.