Concept:The behavior of light acting as discrete, quantized packets of energy (photons) rather than a continuous wave fundamentally shifted modern physics.
Formula:$$ E = hf - \Phi $$
Solution:- The photoelectric effect, explained by Albert Einstein in 1905, demonstrated that electrons are emitted from metals only if incident light exceeds a specific threshold frequency, regardless of intensity.
- This implies light energy is delivered in discrete lumps (particles called photons), rather than accumulating smoothly as a classical wave would predict.
Why other options are incorrect:The Davisson-Germer experiment proved the
wave nature of
matter. Pair-production also involves photons but the photoelectric effect is the classic, historical foundation that earned Einstein the Nobel Prize for the particle nature of light.
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