Question

Energy above ground state

$n=4$ ------------------------------ $E_4=7eV$

$n=3$ ------------------------------ $E_3=6eV$

$n=2$ ------------------------------ $E_2=4eV$

$n=1$ ------------------------------ $E_1=0$

In the above figure, energies of different levels are given. Which of the following photon energies could NOT be emitted from this atom after it has been excited to the $4^{th}$ energy level?

• A. 1 eV
• B. 2 eV
• C. 3 eV
• D. 4 eV
• E. 5 eV

Answer 1

The correct option is E 5 eV

Photon of a particular energy is emitted when transition takes place from a level to a lower energy level with difference being the energy of the photon.

All the energies given in option A, B, C and D are possible to be obtained from transition of electron from a higher energy level to a lower one.

However $5eV$ energy cannot be obtained after any possible transitions from the given states.