Oxygen is it's own element. Air is a combination of elements. That question is not even a sentence, but I think your answer is Air is 19% Oxygen at sea level.
18%
21% of the atmosphere is oxygen.
Air contains abundant oxygen and trace amounts of hydrogen.
99% of air
20.8 percent
The density of oxygen is 1,429 g/L. The density of air is 1,290 g/L.
There is 21% of oxygen in the air.
Air is approximately 20% Oxygen.
About 16% of the air you expel is oxygen.
Concentration of oxygen in dry air is 20,946 %.
21% of the atmosphere is oxygen.
Oxygen - yes. Air - no. Not much of that around underwater.
Air contains abundant oxygen and trace amounts of hydrogen.
About 20% of the volume of the air in the room is oxygen.
A small percent . exhaled air always contains oxygen .
99% of air
ideally 21% (20.95%)
Oxygen, of course.