Such results fit well with Plank's hypothesis of the particle nature of light, as almost every phenomenon involving light could be explained by waves.
Four remarkable aspects of it were noticed after its discovery: there was no time lag for the phenomenon; increasing the intensity of the source increased the number of reactions but not their maximum kinetic energy; red light was unable to cause it; and weak violet light resulted in higher energies than intense light with greater wavelengths. Such results fit well with Plank's hypothesis of the particle nature of light, as almost every phenomenon involving light could be explained by waves. For 10 points, name this effect explained by Albert Einstein in a 1905 paper which won him the 1921 Nobel Prize in Physics.
Four remarkable aspects of it were noticed after its discovery: there was no time lag for the phenomenon; increasing the intensity of the source increased the number of reactions but not their maximum kinetic energy; red light was unable to cause it; and weak violet light resulted in higher energies than intense light with greater wavelengths.
{Photoelectric Effect}