When the sun is low in the sky, light rays pass horizontally through more of the lower atmosphere to reach the earth's surface or an observer's eye. ... Because short-wavelength blue and green light are scattered more than red and yellow light, rainbows at times of sunrise and sunset often display the brightest reds.
That wouod be the ionosphere!
First, find the number of moles of UF6
Avagadro's number = 6.023 x 10^23
Number of moles = 8.0 x 10^26 / Avagadro's number = 8.0 x 10^26 / 6.023 x 10^23 = 1.328 x 10³ moles
Molecular weight of UF6 = Molecular weight of U (238.02891) + Molecular weight of F6 (6 x 18.9984032) = 238.02891 + 113.9904192 = 352.0193292 g/mol
Therefore mass of 8.0 x 10^26 UF6 molecules = 352.0193292 g/mol x 1.328 x 10³ moles = 467.481669 x 10³ grams