Practice question

**Matter waves** wave-like properties of moving particles, macroscopic objects not exhibit measurable wave-like because λ = h/(m v) extremely small for large m, e.g., 1 kg at 1 m/s λ=6.6×10⁻³⁴ m undetectable, for electron 9.11×10⁻³¹ kg at 2×10⁶ m/s λ=0.36 nm measurable via diffraction, de Broglie hypothesis λ = h/p proposed by de Broglie 1924, Davisson-Germer experiment confirmed. K = e V = 1.6 × 10⁻¹⁹ × 50 = 8.0 × 10⁻¹⁸ J . p = √(2 m K) = √(2 × 9.11 × 10⁻³¹ × 8.0 × 10⁻¹⁸) ≈ 3.816 × 10⁻²⁴ kg m/s . λ = (h/p) = (6.63 × 10⁻³⁴/3.816 × 10⁻²⁴)