The diffraction of barium with X-radiation of wavelength 2.29 Ao gives a first-order reflection at 30°. What is the distance between the diffracted planes?

Using Bragg's equation2dsin⁡θ=nλ a=nλ2sin⁡θWhere d is the distance between two diffracted planes, θ the angle to have maximum intensity of diffracted X-ray beam, n the order of reflection, and ), the wavelength.∴ d=1×2.29Å2×sin⁡30∘=2.29Å sin⁡30∘=12