Question

X-rays with wavelength of 2.0 nm scatter from a NaCL crystal with plane spacing of 0.281 nm. Find the scattering angle for the second order maxima.

Answer 1

Explanation:

Wavelength of x-rays = 2 nm

Plane spacing, d = 0.281 nm

It is assumed to find the scattering angle for second order maxima.

For 2nd order, Bragg's law is given by :

$2dsin\theta =n\lambda$

For second order, n = 2

$sin\theta =\frac{n\lambda}{2d} \\Sin\theta =\frac{2\times2}{2\times0.281} \\\theta =\arcsin (7.14)$

Here, θ is not defined. Also, the wavelength of x-rays is more than the plane spacing. It means that it cannot produce any diffraction maximum.