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Proton hopping is the process where a H - atom on a hydronium ion forms a H - bond with the O - atom of a neighboring H ( 2 ) O molecule .
 Chemical: H; Chemical: hydronium; Chemical: H; Chemical: O; Chemical: H ( 2 ) O
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, hydronium, H, O, H ( 2 ) O 
Answer:
 Chemical: H; Chemical: hydronium; Chemical: H; Chemical: O; Chemical: H ( 2 ) O