Particle Nature Of Light

NCERT explains that light exhibits a particle nature whereby its energy is not spread continuously but arrives in indivisible packets called photons, each of energy $h\nu$. When a source is extremely faint, so few photons arrive that a sensitive detector can register each one separately, producing discrete clicks rather than a steady signal. This granular arrival is direct evidence for the quantum, particle-like character of light, complementing its wave behaviour in interference. The option blaming detector malfunction is wrong because the discrete clicks are a genuine and reproducible physical phenomenon, not an artefact. The option about waves vanishing and reappearing is wrong because light does not disappear in transit; rather its energy is inherently quantized. The option about dust blocking the beam is wrong because random obstruction would dim the signal irregularly, not reveal the fundamental one-by-one photon arrival. As stated in NCERT Class 12, Chapter 11, the photoelectric effect and photon detection together confirm the particle nature of radiation. A consistency check confirms that discrete detection events are exactly what a photon picture predicts for very low light levels.