Correct Answer - Option 4 : 0.135 nm
Concept:
Bragg’s Law states that when an X-ray beam are allowed to scatter through a crystalline surface, its angle of incidence θ will reflect with some angle of scattering θ. And when the path difference d is equal to a whole number n, of wavelength.
It can be represented as
2dsinθ =nλ
Calculation:
Given:
d = 0.18 nm, n = 1, θ = 22°
From Bragg’s law:
2d sin θ = nλ
2 × 0.18 × sin 22° = 1 ⋅ λ
λ = 0.13464 nm