X-rays are diffracted by a crystal but not by a diffraction grating because_____________?
Correct answer: D. The wavelengths of X-rays are of the same order of magnitude as the separation between atoms in a crystal
- A. The ions in a crystal are well arranged
- B. The lines in a diffraction grating cannot reflect X-rays.
- C. The penetration power of X-rays is high in a diffraction grating
- D. The wavelengths of X-rays are of the same order of magnitude as the separation between atoms in a crystal
Explanation
X-rays have wavelengths of about 10^-10 m, comparable to the spacing between atoms in a crystal, so the crystal produces Bragg diffraction. A student may choose that crystal ions are well arranged, which is true but incomplete because diffraction requires the wavelength and spacing to be comparable.
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About Optics
Light is studied through reflection, refraction, dispersion, interference, diffraction and polarization, linking ray behavior with its wave nature. Questions may involve mirrors, lenses, optical instruments, refractive index and image formation, while geometrical optics deals with rays and wave optics explains effects such as interference and diffraction.
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