27844
We obtain sub - picometer resolution data from a 50 pm image of graphene , revealing a 1 % axial elongation and a 3 fold symmetry , indicating a chair conformation .
 Chemical: graphene
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: graphene 
Answer:
 Chemical: graphene