7521
This study aimed to assess the bioavailability of copper in soil , by measuring its uptake kinetics into a representative soil invertebrate , the collembolan Folsomia candida .
 Chemical: copper
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: copper