Chapter 6, Problem 113AP

When an electron makes a transition between energy levels of a hydrogen atom, there are no restrictions on the initial and final values of the principal quantum number n. there is a quantum mechanical rule that restricts the initial and final values of the orbital angular momentum l. This is the selection rule, which that 11; that is, in a transition. the value of * can only increase or decrease by 1. According to this rule, which of the following transitions are allowed. $\left(\text{a}\right)\text{ 1}s\to 2s,\left(\text{b}\right)\text{ 2}p\to 1s\text{ ,}\left(\text{c}\right)\text{ 1}s\to \text{ 3}d,\left(\text{d}\right)\text{ 5}d\to \text{ 4}f,\left(\text{e}\right)\text{ 4}d\to 3s\text{?}$ In view of this selection rule, explain why it is possible to observe the various emission series shown in Figure 611.