12755
Atom - thick materials such as single - walled carbon nanotubes ( SWCNTs ) and graphene exhibit ultrahigh sensitivity to chemical perturbation partly because all of the constituent atoms are surface atoms .
 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: carbon; Chemical: graphene