Final answer:
The transition from n=5 to n=1 results in a shorter wavelength than the transition from n=4 to n=2 because it involves a larger difference in energy levels. We use the Rydberg formula to calculate the wavelengths and determine that larger ΔE corresponds to shorter wavelengths.
Step-by-step explanation:
Comparing Emission Line Wavelengths
To determine which transition in a hydrogen atom results in a shorter wavelength emission line, we need to consider the difference in energy levels (ΔE) between the initial and final states of the electron. To find these energy levels, we use the Rydberg formula for calculating the wavelengths of emitted or absorbed radiation:
E = hc/λ = 13.6 eV (1/nm²- 1/nn²)
where λ is the wavelength, h is Planck's constant, c is the speed of light, and E is the energy of the photon.
ΔE
is greater for transitions with larger differences in the principal quantum numbers. Therefore, comparing the transitions n=4 to n=2 and n=5 to n=1:
- For n=4 to n=2, ΔE corresponds to 13.6 eV (1/2² - 1/4²)
- For n=5 to n=1, ΔE corresponds to 13.6 eV (1/1² - 1/5²)
Since the energy difference is larger for the transition from n=5 to n=1, the wavelength for this transition will be shorter than for the n=4 to n=2 transition. In general, shorter wavelengths correspond to larger energy differences between the energy levels involved in the transition.