oxygen
Oxygen makes up about 21% of the air we breathe.
There is approximately 21 % oxygen in our air.
Oxygen makes up 21 percent of the air by volume.
The percent of oxygen in dry air is approximately 21%.
21%
oxygen! There is 21 percent oxygen in inspired ( the stuff you breath in) air and 13 percent in expired(the stuff you breath out)
Oxygen makes up approximately 21% of the air we breathe.
Oxygen makes up approximately 21% of the Earth's atmosphere.
Roughly 21% of the air we breathe is oxygen. Nitrogen makes up about 78% of the air, with the remaining 1% composed of various other gases.
Oxygen makes up about 21% of the Earth's atmosphere. Nitrogen is the most abundant component, making up approximately 78%.
mainly nitrogen (approximately 78 percent) and oxygen (approximately 21 percent) there are approximately 1 percent other gases, which includes carbon dioxide at 0.04 percent (aprrox.)
78 percent Air is mostly gas The air in Earth's atmosphere is made up of approximately 78 percent nitrogen and 21 percent oxygen.