Air

In the early 1800s, John Dalton improved and summarized the initial measurements of the constituents of air, with the exception of argon. The Earth's atmosphere contains 78.09 % nitrogen, 20.94 % oxygen, 0.93 % argon and 0.04 % carbon dioxide. The remaining 0.1% of the Earth’s atmosphere is made up of trace amounts of other elements (neon, helium, krypton, methane, hydrogen, xenon and radon).