In a mixture of `He^(Theta)` gas H atom and `He^(Theta)` ions Are excited to three respective first excited subsepuenly , H atom transfers its total excitation energy to `He^(Theta)`ions by collision .Assuming that Bohr model of an atom is applicable , answer the following question The quantum number n of the statement finaly populated is `He^(Theta)` ion is .

Options

A. 1
B. 2
C. 4
D. 6

Answer

C

Explanation

In `H_(1 rarr 2)` the excitation transfer their excitation energy `(10.2 eV)` to the electron in `He^(o+)`is further excited to say `n = n_(2)` thus` 10.2 = 13.6 xx 2^(2) xx (1//2^(2) - 1//n_(2)^(2))` therefore `n_(1) = 4`