氢原子中量子数n=4状态的绕核旋转半径为 r = 4^2 r0 = 16*5.29*10^-11 m
e^2 / (4π ε0 r^2) = m v^2 / r
v = √(e^2 / (4π ε0 r m))
n = v t / (2π r) = 5.46*10^5