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 composition of air is necessary for life on Earth. It is mostly made of nitrogen, around 78 percent by volume. The second most abundant element is oxygen, required for respiratory processes, which makes up about 21 percent of the atmosphere's air.