Calculate the unsaturation number for each of the compounds: a. The unsaturation number of C3H4Cl4 is: 0 b. The unsaturation number of C4H7Cl is:

Consider hydrogen in an excited state n = 5n=5 that emits photons to reach the ground state. there are various possible transitions other than straight to the ground state that can occur; for example, it can drop to the n = 3n=3 state followed by the n = 3n=3 to the ground state transition. which of the possible transitions will result in the emission of a photon in the visible region?