When photons collide with hydrogen atoms in ground state, the atoms absorb the energy and rise to an excited state. After a time of  ${10}^{-8}$  sec, these atoms release photons to come to the ground state. When the energy of a photon is greater than the ionization energy, it knocks out an electron from a atom. In a certain experiment, a stationary hydrogen atom is being bombarded with a source that a single photon strikes the atom after every few nanoseconds. The incident photons have different energies. The table below indicates the energies of the incident photon at different times. Assume hydrogen atom remains stationary during and after collision.

SI. No.	Time (in nanosecond)	Energy (eV)
1	100	10.2
2	300	12.09
3	400	10.2
4	405	4.8
5	550	12.75
6	700	18

Read the above passage carefully and answer the following questions.