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Graphene , a two - dimensional giant - molecule of sp ( 2 ) - bonded carbon atoms , provides a perfect platform for studying free radical reaction chemistry in two - dimensions , which holds promise to control the chemical functionality of graphene .
 Chemical: Graphene; Chemical: carbon; Chemical: graphene
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: Graphene; Chemical: carbon; Chemical: graphene