The atmosphere of planet Imaginus only has one constituent, the molecule X2, which is in hydrostatic equilibrium at all altitudes. At the surface of the planet, the concentration of X2 is 5×1015 cm3 and the scale height is H = 10 km, for all altitudes. What is the density of X2 at an altitude of 120 km? Report your answer in #/cm3 to 3 significant digits. The density at 120 km is cm3.

The atmosphere of planet Imaginus only has one constituent, the molecule X2, which is in hydrostatic equilibrium at all altitudes. At the surface of the planet, the concentration of X2 is 5×1015 cm3 and the scale height is H = 10 km, for all altitudes. What is the density of X2 at an altitude of 120 km? Report your answer in #/cm3 to 3 significant digits. The density at 120 km is cm3.