Chemistry

Problem

An electron in a hydrogen atom revolves in a circular orbit of radius

2.12\times10^{-10}\,\text{m}

with a speed of

1.09\times10^{6}\,\text{m s}^{-1}

. Taking the mass of the electron as

9.11\times10^{-31}\,\text{kg}

and

h=6.63\times10^{-34}\,\text{J s}

, calculate the principal quantum number

n

of this orbit.