When in hydrogen like ion, electron jumps from n = 3 to n = 1, the emitted photon has frequency `2.7 xx 10^(15)` Hz. When electron jumps from n=4 to n=1, the frequency is

Options

A. `1.6xx10^15` Hz
B. `2.8xx10^15` Hz
C. `6.4xx10^15` Hz
D. `4.8xx10^15` Hz

Answer

B

Explanation

When the electron jumps from n=3 to n=1 orbit,
`upsilon = Rc[1/1^2-1/3^2]` or `2.7xx10^15=Rcxx8/9` ….(i)
When the electron jumps from n=4 to n=1
`upsilon.=Rc[1/1^2-1/4^2]=Rcxx15/16` …(ii)
From eqn (i) and (ii) `(upsilon.)/(2.7xx10^15)=15/16xx9/8`
`upsilon.=15/16xx9/8xx2.7xx10^15=2.8xx10^15` Hz