cfu: define the term allotrope

# Brief Explanations: An allotrope is a form of an element where atoms are bonded in a different way. For example, carbon has allotropes like diamond (tetrahedral bonding) and graphite (layered, hexagonal bonding). The key is that it's the same element but with different structural arrangements of atoms. # Answer: An allotrope is a different structural form of the same element.