2 million years is hardly anything when considering the age of the earth. If you are considering the early earth and its atmosphere you should speak of billions of years.
The inert gases (on earth) are the result of radioactive decay and build up in the atmosphere over time. Argon is (comparatively) rather abundant, Helium and Neon are fairly abundant and have found commercial applications. Xenon, Krypton, and Radon are rare but have been collected and have had an impact on human history. Health nuts use to breath pure Radon and suffer rather gruesome radiation poisoning.
Hydrogen was the most abundant in the early Earth atmosphere - approx. 60 %.
This gas was carbon dioxide.
oxygen
Oxygen.
Nitrogen is the least abundant element in the atmosphere of the Earth. The most abundant element in the atmosphere of the Earth is oxygen.
The atmosphere
Nitrogen, Oxygen, Argon & Carbon Dioxide.
oxygen
oxygen
the least abundant gas in our atmosphere is Argon
Nitrogen is the least abundant element in the atmosphere of the Earth. The most abundant element in the atmosphere of the Earth is oxygen.
The least abundant gas in Earth's atmosphere is argon at 0.93%. The most abundant gas is oxygen at 78%.
Argon at about 1%
Nitrogen.
The atmosphere
Nitrogen, Oxygen, Argon & Carbon Dioxide.
Nitrogen, Oxygen, Argon & Carbon Dioxide.
that sounds unanswerable.
Everywhere, at least on earth and in the earths atmosphere.
The heaviest ones.
oxygen