(a)[3]
Explain how hydrogen’s line spectrum gives evidence that atoms contain discrete electron energy levels.
(b(i))[1]
On Fig. 7.1, draw an arrow to indicate a third possible transition.
(b(ii))[3]
Calculate the wavelength of the light emitted for the transition in (i).
(c)[4]
A beam of light has a continuous range of wavelengths from $400\ \text{nm}$ to $700\ \text{nm}$. This light is directed onto some cool hydrogen gas, as shown in Fig. 7.2. Using the wavelengths found in (b), state and explain what the emergent spectrum looks like.