Question

Find the quantum number that characterizes the earth's orbit around the sun. The earth's mass is 6.0 x 1024 kg, its orbital radius is 1.5 x 1011 m, and its orbital speed is 3.0 x 104 m/s.

Answer 1

According to Bohr's model:

$$mvr=n\frac{h}{2\pi},\\\space\\ n=\frac{2\pi mvr}{h}=2.56·10^{74}.$$