The energy-level scheme for the hypothetical one electron element Bansalium is shown in figure. The potential energy is taken to be zero for an electron at an infinite distance from the nucleus.

If photons emitted from Bansalium transitions `n=4 rightarrow n=2 and from n=2 rightarrow n=1` will eject photoelectrons from an unknown metal but the photon emitted from the transition `n=3 rightarrow n=2` will not, what are the limits (maximum and minimum possible values) of the work function of the metal ?

Options

A. `8 eVlt philt10eV`
B. `5eVltphi lt 10 eV`
C. `5 eV lt phi lt 8 eV`
D. `5 eV lt phi lt 12 eV`

Answer

C

Explanation

`E_(4rightarrow2)=8eV`
`E_(2rightarrow1)=10eV`
`philt8eV`
`E_(3rightarrow2)=5eV`
`phigt5eV`