Figure 6.11 Line spectra of hydrogen and neon. The colored lines occur at wavelengths present in the emission. The black regions are wavelengths for which no light is produced in the emission. н 550 600 650 400 450 500 700 nm Ne 500 700 nm 550 400 450 600 650

The visible emission lines observed by Balmer all involved
n_f = 2. (a) Which of the following is the best explanation of
why the lines with n_f = 3 are not observed in the visible portion
of the spectrum: (i) Transitions to n_f = 3 are not allowed
to happen, (ii) transitions to n_f = 3 emit photons in the
infrared portion of the spectrum, (iii) transitions to n_f = 3
emit photons in the ultraviolet portion of the spectrum, or
(iv) transitions to n_f = 3 emit photons that are at exactly the
same wavelengths as those to n_f = 2. (b) Calculate the wavelengths
of the first three lines in the Balmer series—those for
which n_i = 3, 4, and 5—and identify these lines in the emission
spectrum shown in Figure 6.11.