In spectroscopy, electrons absorb photons and rise to higher energy levels; Emit photons and drop to a low energy level.

E 1, E2, E3, E4 and E5 are the energy levels of electrons, that is, the only possible state (electrons cannot exist in the intermediate state of E 1 and E2), so when electrons jump, they jump from one energy level to another. If E 1 absorbs the light of V2, its energy can't reach E2 level, and it can only be in the middle, but there is no state in the middle, so it won't be absorbed. And v 1 will be absorbed. After E 1 is absorbed, the electrons jump directly to E3.

When the electron reaches E3, if it is unstable, it will jump to E2 and E 1 and release energy (emit photons).

So the answer is v 1, (E3-E2)/h (E3-e1)/h.

Note: Because it is college physics, the transfer criteria are not considered.