Which of the following phenomena can only be explained by considering the wave nature of light?

• A. Interference
• B. Photoelectric effect
• C. Compton scattering
• D. Emission of atomic spectra

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the dual nature of light, which exhibits both wave-like and particle-like properties. Different phenomena highlight one aspect more clearly than the other.
2. Step 2: Review the photoelectric effect, which involves electrons being ejected from a metal surface when light shines on it. This effect is best explained by the particle nature of light (photons) rather than its wave nature.
3. Step 3: Consider Compton scattering, where X-rays scatter off electrons and show a change in wavelength. This phenomenon also supports the particle nature of light, as it involves collisions between photons and electrons.
4. Step 4: Examine the emission of atomic spectra, which results from electrons transitioning between energy levels in atoms. This process is explained by quantum mechanics and the quantized energy levels of electrons, not directly by the wave nature of light.
5. Step 5: Focus on interference, which occurs when two or more light waves overlap and combine to form a pattern of constructive and destructive interference. This phenomenon can only be explained by considering the wave nature of light, as it relies on the superposition principle unique to waves.