which of the following elements makes up the majority of the atmosphere's content?
The Composition of Our Atmosphere â What Is In The Air. The most abundant gases found in our atmosphere are nitrogen and oxygen. Nitrogen makes up around 78% of the total atmosphere, while oxygen makes up 21%. The remaining 1% is made up mostly of a gas called argon. This means that with each breath you take you are breathing 78% nitrogen, 21% oxygen and 1% argon, with trace amounts of other gases, such as methane, hydrogen, helium, neon, krypton, carbon dioxide, and a form of oxygen known as ozone.