Final answer:
For two hydrogen atoms each in the third excited state, the maximum number of different photons emitted as they transition to lower energy levels is 3; since they can each transition from n=4 to n=3, n=4 to n=2, and n=4 to n=1.
Hence, the correct answer is: B. Maximum number of different photons emitted is 3
Step-by-step explanation:
If there are only two hydrogen atoms, each in the third excited state, we can determine the number of different photons that can be emitted as they return to lower energy states. The third excited state for a hydrogen atom corresponds to the n=4 energy level ( because the ground state is n=1, first excited is n=2, and so on). When the electron transitions from a higher energy state to a lower energy state, it emits a photon with energy equal to the difference in energy between those two states.
An electron can transition from the n=4 level to the n=3, n=2, or n=1 levels, emitting photons with different energies for each transition. So, for each hydrogen atom, there can be three different photon emissions. However, since the question only asks for the maximum number of different photons, we count the unique transitions across both atoms. The transitions are n=4 to n=3, n=4 to n=2, and n=4 to n=1 for both atoms, resulting in three unique photon energies. Hence, the correct answer is: B. Maximum number of different photons emitted is 3