Atoms and Nuclei Part 2

As we know that, the velocity of electron in the nth shell of hydrogen atom is given by
vn=‌

Ze2

2ε0nh

where, Z= atomic number,
n= order of orbit,
e= charge on an electron,
h= Planck's constant
and ε0= absolute permittivity of free space
⇒‌‌vn∝‌

1

n