3. Find whether the following transitions are allowed, and if they are, find the energy involved and whether the photon is absorbed or emitted for the hydrogen atom: (a) (5, 2, 1,%) → (5, 2, 1, -1) (b) (4, 3, 0, 1) (4, 2, 1,-) (c) (5, 2, -2,-2)→→ (d) (2, 1, 1, %)→→ (4, 2, 1, %) (1, 0, 0, -1)

3. Find whether the following transitions are allowed, and if they are, find the energy involved and whether the photon is absorbed or emitted for the hydrogen atom: (a) (5, 2, 1,%) → (5, 2, 1, -1) (b) (4, 3, 0, 1) (4, 2, 1,-) (c) (5, 2, -2,-2)→→ (d) (2, 1, 1, %)→→ (4, 2, 1, %) (1, 0, 0, -1)