20734
In the second part of the study , the various x , y - ionenes ( x , y are numbers of methylene groups between the adjacent charges ) with fluoride , bromide , and iodide counterions are mixed with aqueous sodium sulfate solution .
 Chemical: methylene; Chemical: fluoride; Chemical: bromide; Chemical: iodide; Chemical: sodium sulfate
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: methylene; Chemical: fluoride; Chemical: bromide; Chemical: iodide; Chemical: sodium sulfate