In a Compton scattering experiment, the scattered photon has a wavelength of 6.55 pm. If the scattering angle is 50°, what was the wavelength of the incident photon?
A) 5.68 pm
B) 7.42 pm
C) 3.28 pm
D) 0.868 pm
E) 2.43 pm

Question

Quizplus · Accepted Answer

The wavelength of the incident photon can be calculated using the Compton scattering formula: $\Delta \lambda = \lambda' - \lambda = \frac{h}{m_e c} (1 - \cos \theta)$, where $\Delta \lambda$ is the change in wavelength, $\lambda'$ is the wavelength of the scattered photon, $\lambda$ is the wavelength of the incident photon, $h$ is Planck's constant, $m_e$ is the electron mass, $c$ is the speed of light, and $\theta$ is the scattering angle. Rearranging for $\lambda$, we get $\lambda = \lambda' - \frac{h}{m_e c} (1 - \cos \theta)$. Given $\lambda' = 6.55$ pm and $\theta = 50^\circ$, and knowing the values of $h$, $m_e$, and $c$, we can calculate the initial wavelength. The calculation shows that the initial wavelength is shorter than the scattered wavelength, which matches option A, 5.68 pm, after performing the specific calculation with the given angle.

In a Compton Scattering Experiment, the Scattered Photon Has a Wavelength