This was not a prominent gas in the Earth's early atmosphere
A) methane.
B) ammonia.
C) hydrogen.
D) helium.
E) oxygen.
Question 2
This is the most fundamental reason why Earth currently has an atmosphere
A) strong winds keep the atmosphere moving horizontally above the Earth.
B) the Earth's magnetic field prevents gas molecules from escaping into space.
C) the Earth's gravity is strong enough to prevent most gases from escaping into space.
D) Earth's atmosphere is quite dense, and thus very viscous.
E) the solar wind constantly adds gas particles to the atmosphere.
Uranus's aurorae against its equatorial rings, imaged by the Hubble telescope. Unlike the auror
Early in the twentieth century, when malnutrition was common, companies such as this one advertised
Distance from Earth to Sun schematic
Earth’s Revolution
Catabolism of uric acid to ammonia and CO2
Earth’s Lithospheric Plates