30021
Helium nanodroplets are widely used as a cold , weakly interacting matrix for spectroscopy of embedded species .
 Chemical: Helium
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: Helium 
Answer:
 Chemical: Helium