Electrons can be scattered from the surface of a metal to form a diffraction
pattern. This shows that:
Electrons can behave like waves
Electrons have charge
Electrons can behave like waves and particles
Electrons can behave like particles
Electron diffraction from a metal surface demonstrates that electrons can behave like waves and particles, confirming wave-particle duality in quantum physics. This phenomenon, observed in experiments like Davisson-Germer in 1927, shows electrons producing interference patterns identical to waves when scattered by crystal lattices. The correct answer is “Electrons can behave like waves and particles”.
Option Analysis
- Electrons can behave like waves: This captures the diffraction pattern, a hallmark of wave interference, as electrons scatter elastically from atomic planes, forming rings or spots. However, it ignores particle properties like charge and discrete detection.
- Electrons have charge: While true (electrons are negatively charged), this does not explain diffraction, which requires wave nature for interference, not just electrostatic interactions.
- Electrons can behave like waves and particles: Accurate, as diffraction reveals wave behavior (λ = h/p), while electrons arrive as discrete particles on screens. This duality is central to quantum mechanics.
- Electrons can behave like particles: Particles would scatter randomly without interference; the observed pattern rules this out alone.
Davisson-Germer Experiment
Electrons accelerated by voltage V (energy eV = ½mv²) strike a nickel crystal, diffracting like X-rays per Bragg’s law (nλ = 2d sinθ). Patterns match de Broglie’s hypothesis, with wavelength shrinking as speed increases, proving matter waves. No pattern occurs without wave properties, distinguishing from classical particles.
Wave-Particle Duality Implications
Complementarity principle states electrons show wave traits in diffraction setups and particle traits in photoelectric effects. This duality applies to all matter, scaling with mass and velocity.
