Which one of the following is the purest form of Carbon ?

Carbon exists in various allotropic forms, categorized into crystalline and amorphous types. Crystalline allotropes like diamond, graphite, and fullerenes consist of carbon atoms arranged in specific, regular lattices [1]. Among the options provided, charcoal, coke, and carbon black are considered amorphous or microcrystalline forms of carbon that typically contain impurities such as hydrogen, oxygen, and mineral ash derived from their organic precursors. In contrast, fullerenes (such as C60) are pure carbon molecules where carbon atoms are arranged in a closed cage-like structure, such as a football shape [1]. Because fullerenes are discrete molecules composed entirely of carbon atoms without the residual impurities found in industrial carbon products like coke or charcoal, they are considered the purest form of carbon among the given choices [1].

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 4: Carbon and its Compounds > Allotropes of carbon > p. 61