According to Bohr's theory of hydrogen atom , the product of the binding energy of the electron in the nth orbit and its radius in the nth orbit

Options

A. is proportional to `n^(2-)`
B. is inversely proportional to `n^(3)`
C. has a constant value of `10.2eVÅ`
D. has constant value `7.2eVÅ`

Answer

D

Explanation

Binding energy of electron is given by
`E_(n)prop1/(n^(2))`, where n represents number of Bohr.s orbit.
And radius of Bohr.s orbit is given by
`r_(n)propn^(2)`
`:.E_(n)r_(n)` is independent of n
Hence
`E_(1)r_(1)=(13.6eV)(0.53Å)=7.2eVÅ`
= constant