What is the difference between energy and intensity as far as light waves are concerned?
Energy of a wave is all the energy of that wave. So over the entire time the wave is transmitted, all of the energy broadcast. Intensity is the power per square meter. Power is energy per second.
Is reflection A photoelectric effect?
Most commonly observed phenomena with light can be explained by waves. But the photoelectric effect suggested a particle nature for light. That worked fine for reflection, because the bouncing of either particles or waves off a planar surface follows the same law of reflection.
What is the photoelectric effect and how did it change our concept of light and matter?
The photoelectric effect is the emission of electrons when electromagnetic radiation, such as light, hits a material. An alteration in the intensity of light would theoretically change the kinetic energy of the emitted electrons, with sufficiently dim light resulting in a delayed emission.
Why does the photoelectric effect prove that light is a particle?
The photoelectric effect proves that light has particle-like activity. The photoelectric effect happens when photons are shone on metal and electrons are ejected from the surface of that metal. The electrons that are ejected are determined by the wavelength of light which determines the energy of photons.
What is the difference between intensity of light and energy of light?
The Energy of light (electromagnetic radiation) is calculated using the equation . The intensity of light, when defining light as a particle is the number of photons present at any given time. When light is defined as a wave the intensity is the square of the amplitude ( ).
Is intensity of light and energy Same?
Intensity of light is defined as the energy transmitted per unit area in one unit of time. Then the intensity of the light at the surface of the spherical source is equal to the energy emitted by it per unit time through a unit area of its surface.
How are reflection and refraction explained by the wave models of light?
When a beam of light travels between two media having differing refractive indices, the beam undergoes refraction, and changes direction when it passes from the first medium into the second. Huygens believed that ether vibrated in the same direction as light, and formed a wave itself as it carried the light waves.
What does the photoelectric effect show about the properties of light?
What does light do in the photoelectric effect answers?
When light shines on a metal, electrons can be ejected from the surface of the metal in a phenomenon known as the photoelectric effect. This process is also often referred to as photoemission, and the electrons that are ejected from the metal are called photoelectrons.
Does the photoelectric effect prove that light is a wave or particle?
Photoelectric effect occurs when a high energy photon (light particle) strikes a metal surface and an electron is ejected while the photon disappears. This shows that light can be a particle AND a wave.
What is the photoelectric effect in physics?
Predictions based on light as a wave. To explain the photoelectric effect, 19th-century physicists theorized that the oscillating electric field of the incoming light wave was heating the electrons and causing them to vibrate, eventually freeing them from the metal surface.
What is the relationship between energy and frequency of a photon?
According to Planck’s equation, the energy of a photon is proportional to the frequency of the light, . The amplitude of the light is then proportional to the number of photons with a given frequency. Concept check: As the wavelength of a photon increases, what happens to the photon’s energy?
What are the effects of wave frequency on photoemission?
The effects of wave frequency on photoemission. The frequency of red light (left) is less than the threshold frequency of this metal , so no electrons are ejected. The green (middle) and blue light (right) have , so both cause photoemission.
What are photoelectrons and how do they work?
This process is also often referred to as photoemission, and the electrons that are ejected from the metal are called photoelectrons. In terms of their behavior and their properties, photoelectrons are no different from other electrons. The prefix, photo-, simply tells us that the electrons have been ejected from a metal surface by incident light.