3537
The isotopes Xe and Xe are predicted by theory to undergo double beta decay , but this has never been observed so they are considered stable .
 location: Xe; location: Xe
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities: Xe, Xe 
Answer:
 location: Xe; location: Xe