4273
( 23 ) Na nuclear magnetic resonance ( NMR ) spectroscopy was used to study the molecular mobility of sodium ions in model cheeses through measurements of the relaxation and creation times .
 Chemical: ( 23 ) Na; Chemical: sodium
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: ( 23 ) Na; Chemical: sodium