One of the most significant conclusions that was drawn from the photelectric effect experiments is that light
Select one:
a. has momentum
b. is quantized, or comes in packets that we now call photons
c. is a particle (that we now call a photon)
d. has mass that causes electrons to jump off the photo-surface like poolballs
The correct answer and explanation is:
The correct answer is b. is quantized, or comes in packets that we now call photons.
The photoelectric effect experiments, first explained by Albert Einstein in 1905, showed that light behaves as though it is made up of discrete packets of energy, which are now called photons. This discovery was crucial in understanding the dual nature of light, meaning that it has both particle-like and wave-like characteristics.
Before Einstein’s work, light was thought to be purely a wave, as suggested by classical wave theory. However, the photoelectric effect couldn’t be explained by this theory. According to the wave theory, the energy of light should depend on the intensity (brightness) of the light, not on its frequency. Yet, experiments showed that when light of a certain frequency (or higher) strikes a metal surface, electrons are emitted from that surface. For lower-frequency light, no electrons were emitted, no matter how bright the light was.
Einstein proposed that light actually consists of energy quanta (or photons) and that each photon has energy proportional to its frequency, according to the equation E = hf, where E is the energy of the photon, h is Planck’s constant, and f is the frequency of the light. When a photon strikes the metal surface, its energy is transferred to an electron. If the photon’s energy is high enough (i.e., if the light has a high enough frequency), it can cause the electron to be emitted from the metal. This explained why light below a certain frequency couldn’t release electrons, regardless of its intensity.
Thus, the key conclusion from the photoelectric effect is that light is quantized, meaning it exists in discrete packets of energy (photons), which was a major step in the development of quantum mechanics.