The Earth's atmosphere is composed of roughly 21% oxygen. This level of oxygen in the air is ideal for human respiratory needs.
Around 16% of the air you breathe out is oxygen. This percentage decreases from the 21% of oxygen in the air you inhale due to the exchange of gases that occurs during respiration.
21% Oxygen, 78% Nitrogen, 1% other gasses in out atmosphere.
Air is a mixture of gases, including oxygen, nitrogen, carbon dioxide, and others, whereas oxygen is a single element found in the air. The air we breathe typically contains about 21% oxygen along with other gases. Oxygen is essential for most living organisms to survive, while air is the combination of gases present in the Earth's atmosphere.
The air is made up, mostly, of oxygen and nitrogen.. Air is 78 % nitrogen, 21 % oxygen, about 1 % argon, and a whole raft of other gases present in even smaller amounts..
Air is approximately 20% Oxygen.
Oxygen - yes. Air - no. Not much of that around underwater.
The Earth's atmosphere is composed of roughly 21% oxygen. This level of oxygen in the air is ideal for human respiratory needs.
About 20% of the volume of the air in the room is oxygen.
Around 16% of the air you breathe out is oxygen. This percentage decreases from the 21% of oxygen in the air you inhale due to the exchange of gases that occurs during respiration.
A small percent . exhaled air always contains oxygen .
There is about 21% oxygen in the air we breathe regardless of the time of day. The concentration of oxygen remains relatively constant throughout the day.
ideally 21% (20.95%)
Oxygen, of course.
The concentration of oxygen in the air is much much higher than in the water. This make obtaining oxygen much easier and strenuous activity (to a level higher than that is water) possible.
Oxygen keeps animals alive, Nitrogen is not much use.
In 1973, the composition of Earth's atmosphere was roughly the same as it is today, with oxygen making up about 21% of the air.