Consider the radiation emitted by large number of singly charged positive ions of a certain element. The sample emit fifteen types of spectral line. One of which is same as the first line of lyman series. What is the binding energy in the highest energy state of this configuration ?

Options

A. `13.6 eV`
B. `54.4 eV`
C. `10.2 eV`
D. `1.6 eV`

Answer

D

Explanation

`(n(n-1))/(2) = 15 rArr n = 6` Element should be hydrogen like atoms so ions wll be `He^(+)`
Binding energy `= (13.6)(Z^(2))/(n^(2)) = ((3.6)(4))/(36) = (13.6)/(9) = 1.6 eV`