Which of the following is used to study the arrangement of particles in crystal lattices?

Correct answer: X-rays.

Explanation: X-rays have wavelengths on the order of interatomic spacings in crystals (~10⁻¹⁰ m). When X-rays strike a crystal, they are diffracted by the regularly spaced planes of atoms, producing patterns that reveal how particles are arranged (X-ray crystallography, using Bragg’s law \(n\lambda = 2d\sin\theta\)).

• Alpha-particles and Beta-particles: charged particles that interact too strongly with matter; they don’t give clean diffraction patterns for crystal structure determination.
• Gamma-rays: far more energetic and penetrating; their wavelengths are typically much shorter and are not commonly used for routine crystal structure studies.
• X-rays: best suited for studying crystal lattices due to suitable wavelength and established diffraction techniques.