Predictions of the wave model: Energy of light was dependent on the amplitude of the light wave, which was manifested as the brightness of the light. Higher amplitude (brighter) light would cause the ejected electrons to be more energetic. Colour of light was dependent on the frequency of the light but frequency had no bearing on the energy of the ejected photons. Predictions of the photon model: Both the energy of light and the colour of light was dependent on the frequency of the photons. Higher frequency would cause the the ejected electrons to be more energetic. The number of photons was manifested as the brightness of the light. Higher number of photons (brighter) light would cause the ejected electrons to be more numerous (higher current). Observations from the photoelectric effect experiment: Ejected electron energy was directly related to the frequency of the light and brighter light resulted in higher current. These observations were explained by the photon model and could not be explained with the wave model.
No metal will release electrons until an EM radiation of frequency greater than the threshhold frequency is incident on it. According to the wave theory, if energy is supplied to the metal continuously then eventually the metal will release electrons, irrespective of the frequency of the wave which is incident on the metal. The observation predicted by the wave theory does not happen in experiment.
The photoelectric effect is a phenomena that can only be explained by the particle model.
The particle model of light entails that light consists of tiny packages of energy called photons. Because light is an electromagnetic wave the model is a part of the general model for electromagnetism. This model is called Quantum Electrodynamics, or QED in short.
The Photoelectric Effect and the Compton effect, both of these effects are explained by Photons.
Albert Einstein in his 1905 paper on the photoelectric effect. Summarize as saying that when a photon strikes a metal it will cause electron flow. Wilhelm Hallwachs made the first photocells. An alloy of metals made the first photoresistors. Then solar cells. Albert did not "invent" the effect, it was already known, but he EXPLAINED how it works.
The particle model explains compton scattering and the photo-electric effect perfectly, which the wave model utterly fails to do. The full spectrum of blackbody radiation can be easily derived with the particle model of light, but not with the wave model.
The photoelectric effect is a phenomena that can only be explained by the particle model.
The particle model of light entails that light consists of tiny packages of energy called photons. Because light is an electromagnetic wave the model is a part of the general model for electromagnetism. This model is called Quantum Electrodynamics, or QED in short.
The Photoelectric Effect and the Compton effect, both of these effects are explained by Photons.
Albert Einstein in his 1905 paper on the photoelectric effect. Summarize as saying that when a photon strikes a metal it will cause electron flow. Wilhelm Hallwachs made the first photocells. An alloy of metals made the first photoresistors. Then solar cells. Albert did not "invent" the effect, it was already known, but he EXPLAINED how it works.
The particle model explains compton scattering and the photo-electric effect perfectly, which the wave model utterly fails to do. The full spectrum of blackbody radiation can be easily derived with the particle model of light, but not with the wave model.
It does not explain the photoelectric effect. According to the wave theory, given light of sufficient intensity, electrons should be emitted from the surface of a metal. What is observed though, is that given light of sufficient frequency, electrons will be emitted from the metal surface independent of intensity. If the frequency is too low, electrons will NOT be emitted even if the highest intensity of light was used. Albert Einstein suggested that it would be possible to explain the photoelectric effect if light was considered to be made up of particles instead of waves. The energy of the particles of light, called photons, would be proportional to the frequency of the light. Electrons would be emitted from the metal only if the energy of ONE photon was sufficient for the electron on the metal surface to break bonds and escape from the surface. Otherwise, the photons will rebound on the metal surface with no emission of electrons. Einstein 'mathematised' the photoelectric effect in the following equation: hf = Ekmax + o where h is the planck constant f is the frequency of the radiation Ekmax is the maximum kinetic energy of the emitted electrons o is the work-function energy, that is the minimum energy required for the electron to escape from the metal surface. Note: hf is the energy of a photon. It was for the explanation of the photoelectric effect that Einstein was awarded the Nobel prize in Physics in 1921. (and not for his still greater discoveries in relation to relativity)
QuantumIt supports the quantum model. Einstein received the Nobel Prize in 1921 for this 1905 discovery that light ( as photoelectric energy ) arrives in bundles, each bundle or " quantum " carries a certain amount of energy E=hf where f=frequency of light and H is Plancks constant or 6.626x10-34 j-s ( that's 10 to the minus 34 power)
Account on model state and central library
supports photon particle model as E=hf is supplied in discrete corpuscular quanta; increasing Intensity below fo gives no photoemission (not cumulative as suggested by wave theory- theoretically there will only be delay until photoemmission)
supports photon particle model as E=hf is supplied in discrete corpuscular quanta; increasing Intensity below fo gives no photoemission (not cumulative as suggested by wave theory- theoretically there will only be delay until photoemmission)
A model relating to Food security and agriculture should show how the future of the climate will effect crops. The model must take into account many variables, such as how the climate can lead to different planting and harvesting times and amounts.
additive model = in which the combined effect of the explanatory variables is equal to the sum of their separate effects.multiplicative model = A model in which the joint effect of two or more causes is the product of their effects if they were acting alone.