19400
Strong fluorescence quenching was also observed with high redox potential metal ions such as Ag ( + ) , Au ( 3 + ) , Cu ( 2 + ) and Hg ( 2 + ) , but not with low redox potential ions .
 Chemical: Ag ( + ); Chemical: Au ( 3 + ); Chemical: Cu ( 2 + ); Chemical: Hg ( 2 + )
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: Ag ( + ); Chemical: Au ( 3 + ); Chemical: Cu ( 2 + ); Chemical: Hg ( 2 + )