From FDRâs brushes with death to Eleanorâs midnight ride with Amelia Earhart, here are 10 things you may not know about this presidential pair. 1. Franklin Roosevelt was related to 11 other presidents.
By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor, on average around 1% at sea level, and 0.4% over the entire atmosphere.y volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor, on average around 1% at sea level, and 0.4% over the entire atmosphere.
Density of Nitrogen and Air   If you are asking whether nitrogen is less dense than air and will float on top of it, then yes, nitrogen is lighter, albeit only slightly â¦ . More accurately, nitrogen, which is a constituent gas of air, is less dense than air, not lighter.   The density of air at standard temperature and pressure is 1.292 kg/m3. The density of nitrogen is 1.251 kg/m3.