2637
The absorption rate constant of nanosised and conventional oxygen scavenger were 0 . 45 +/- 0 . 044h ( - 1 ) and 0 . 05 +/- 0 . 006h ( - 1 ) , respectively .
 Chemical: oxygen
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: oxygen