X-rays of wavelength 1.25 Angstroms are incident upon a crystal face in a Bragg refraction experiment.If the crystal spacing is known to be 2.14 angstroms,at what angle should a detector relative to the initial beam direction be placed in order to catch the refracted X-rays?

Question

Quizplus · Accepted Answer

Bragg's law is given by $n\lambda = 2d\sin\theta$, where $n$ is the order of reflection (usually taken as 1 for the first order), $\lambda$ is the wavelength of the incident X-rays, $d$ is the spacing between the crystal planes, and $\theta$ is the angle of incidence (and reflection). Given $\lambda = 1.25$ Angstroms and $d = 2.14$ Angstroms, solving for $\theta$ when $n = 1$ gives $\theta \approx 17^\circ$. Therefore, the detector should be placed at $2\theta = 34^\circ$ relative to the initial beam direction to catch the refracted X-rays.

X-Rays of Wavelength 1 ∘\circ∘ B)34 ∘\circ∘ C)36 ∘\circ∘ D)72 ∘\circ∘

X-Rays of Wavelength 1 $\circ$
B)34^$\circ$
C)36^$\circ$
D)72^$\circ$