Assertion: hemoglobin's oxygen | /r/HasProperty | 20.9 percent
Facets:
Source sentences:
text: Air is a mixture of gases, primarily nitrogen (N 2 ; 78.6 percent), oxygen (O 2 ; 20.9 percent), water vapor (H 2 O; 0.5 percent), and carbon dioxide (CO 2 ; 0.04 percent).