17250
Rougher surface was obtained in gelatin films prepared from skin bleached with H ( 2 ) O ( 2 ) concentrations above 4 % .
 Chemical: H ( 2 ) O ( 2 )
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: H ( 2 ) O ( 2 ) 
Answer:
 Chemical: H ( 2 ) O ( 2 )