The Earth's atmosphere is primarily composed of:

* nitrogênio (n2): Cerca de 78%
* oxigênio (O2): Cerca de 21%

These two gases make up the vast majority of the atmosphere.

The remaining 1% is made up of other gases, including:

* Argônio (AR): About 0.93%
* dióxido de carbono (CO2): About 0.04%
* Neon (Ne), Helium (He), Krypton (Kr), Xenon (Xe), Hydrogen (H2), Ozone (O3): Trace amounts

It's important to note that the percentages can fluctuate slightly depending on location and altitude.