18820
The approach employs ozone to produce fully oxidized alpha - Fe2O3 or a milder oxidant , H2O2 , to generate the Fe ( 2 + ) / Fe ( 3 + ) spinel , Fe3O4 .
 Chemical: alpha - Fe2O3; Chemical: H2O2; Chemical: Fe ( 2 + ); Chemical: Fe ( 3 + ); Chemical: Fe3O4
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: alpha - Fe2O3; Chemical: H2O2; Chemical: Fe ( 2 + ); Chemical: Fe ( 3 + ); Chemical: Fe3O4