1990
The formulas below are valid for all three isotopes of hydrogen , but slightly different values of the Rydberg constant ( correction formula given below ) must be used for each hydrogen isotope .
 person: Rydberg
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: Rydberg 
Answer:
 person: Rydberg