Chemistry

Problem

Which of the following expressions correctly gives the allowed radius

r_{n}

of an electron in the

n

th orbit of a hydrogen-like ion with atomic number

Z

in terms of the Bohr radius

a_{0}

? a)

r_{n}=Z n^{2} a_{0}

r_{n}=\dfrac{n^{2}}{Z}\,a_{0}

r_{n}=n^{2} a_{0}

r_{n}=\dfrac{n^{2}}{Z^{2}}\,a_{0}