Answer:
Step-by-step explanation:
When an electron in a hydrogen atom transitions from the fifth energy level (n = 5) to the second energy level (n = 2), the photon emitted has a wavelength of 434 nanometers. This wavelength is in the visible region of the electromagnetic spectrum, and corresponds to the color blue.
The following table shows the colors of light emitted for various electron transitions in a hydrogen atom:
Energy level transition Wavelength (nm) Color
5 → 2 434 Blue
4 → 2 486 Green
3 → 2 656 Red