1390
Cl occurs in trace quantities in nature as a cosmogenic nuclide in a ratio of about ( 7 – 10 ) " × " 10 to 1 with stable chlorine isotopes : it is produced in the atmosphere by spallation of Ar by interactions with cosmic ray protons .
 location: Ar
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: Ar 
Answer:
 location: Ar