No, the photoelectric effect does not provide evidence that light is exclusively a wave instead of a particle. In fact, the photoelectric effect was one of the experiments that led to the development of quantum mechanics, which recognizes that light can exhibit both wave-like and particle-like behavior, depending on the specific experiment or observation.
The photoelectric effect refers to the phenomenon where electrons are emitted from a material when it is exposed to light of a sufficiently high frequency. This effect was explained by Albert Einstein in 1905, who proposed that light consists of discrete packets of energy called photons, which behave like particles. The energy of each photon is directly proportional to the frequency of the light wave, according to the equation E = hf, where E is the energy, h is Planck's constant, and f is the frequency.
The photoelectric effect demonstrated that light can transfer its energy in discrete amounts (quanta), indicating particle-like behavior. However, it does not provide conclusive evidence that light is exclusively a particle or exclusively a wave. The wave-particle duality of light and other subatomic particles is a fundamental concept in quantum mechanics, and both aspects are observed and studied in various experiments.
Other experiments, such as double-slit experiments and interference patterns, provide evidence for the wave-like behavior of light, showing that light can exhibit interference and diffraction, characteristics that are typically associated with waves. Therefore, it is more accurate to say that the photoelectric effect, along with other experiments, supports the understanding that light exhibits both particle-like and wave-like properties, depending on the context of the experiment or observation.