Final answer:
To calculate the wavelength of a spectral line from a transition between energy levels n=4 and n=2 in the hydrogen atom spectrum, use the equation λ = R(1/n^2 - 1/m^2).
Step-by-step explanation:
To calculate the wavelength of a spectral line produced when an electron undergoes a transition from energy level n=4 to the level n=2, we can use the equation for the wavelengths of the lines of light in the hydrogen atom spectrum. The equation is:
λ = R(1/n2 - 1/m2)
where λ is the wavelength, R is the Rydberg constant, and n and m are the initial and final energy levels, respectively. Plugging in the values n=4, m=2, and the appropriate value for R, we can calculate the wavelength.