Q.

Which of the following is not an allotropic form of carbon

1 Fluorine  
2 Fullerene  
3 Diamond  
4 Graphite  

Ans.

(1)

Carbon is found in many forms in nature which differ from each other in various physical properties but they exist in same state. These forms of carbon are known as allotropes of carbon. From the given options, fullerene, diamond, graphite are all different types of allotropes. Whereas, fluorine is a non-metal which belongs to halogen family. Hence, fluorine is not an allotrope of carbon.