A hydrogen atom in the `4th` excited state, then:

Options

A. the maximum number of emitted photons will be `10`
B. the maximum number of emitted photon will be `6`
C. it can emit three photons in ultraviolet region
D. if an infraed photon is generated, then a visible photon may follow this infared photon

Answer

D

Explanation

The hydrogen atom is in `n = 5` state.
`:.` Max. no of possible photons `=4`
To emit photon in ultra violet region, it must jumps to `n = 1`, because only Lyman series lies in `u.v.` region. Once it jumps to `n = 1` photon, it reaches to its ground state and no more photons can be emitted. So only one photon in `UV` range can be emitted.
If `H` atom emits a photon and then another photon of Balmer series, option `(d)` will be correct.