7340
The formation of Co ( 3 ) O ( 4 ) nano - scale colloid particles by gamma irradiation of CoSO ( 4 ) solutions was investigated .
 Chemical: Co ( 3 ) O ( 4 ); Chemical: CoSO ( 4 )
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: Co ( 3 ) O ( 4 ); Chemical: CoSO ( 4 )