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.
The air in our atmosphere contains a varying amount of water vapor, depending on the weather. When it's hot and humid, evaporated water can make up as much as 6 percent of the air we breathe. On cold, dry days it can be as low as .07 percent of the air's makeup [source: U.S. Department of Energy ].