Wave Particle Duality

What is Wave Particle Duality?

Based on the idea that light and all other electromagnetic Radiation may be considered a particle or a wave nature, Louis de Broglie suggested that the same kind of duality must be applicable to matter. He proposed that any particle of matter having momentum (p) Has an associated wavelength (λ).

Early in this century, physicists began to realize the extent to which both models describe the same phenomena. Waves can be described as particles; particles, as waves. Diffraction and interference phenomena reveal a wave- like character in light, but the photoelectric effect shows light to have a particle like character as well. Electrons have mass but can be diffracted like caves. All particles turn out to have a wavelike character described by de Bmplie whelenths. Nature reveals a particle duality and ambiguity uncharacteristic of science. While the meaning of this wave-particle duality remains a subject of intense debate, many physicists now accept the Bohr complement- yarn principle. The two models exclude one another, yet both are necessary for a complete description  of nature.

Wave Particle Duality

According to Planck’s Hypothesis of the Quantum Theory, the energy is emitted in quanta, which are little packets of energy. He states that energy emitted is related to the frequency of the emitted light and this can be considered as Wave Particle Duality definition. According to Planck’s hypothesis, the quantum energy is related to the frequency by the equation E = hν.

Observing a light is one of the easiest ways to prove the duality between a particle and a wave. Since light is similar to waves, it is able to diffract, refract, and interface, etc.

Albert Einstein’s theory of photoelectric effect significantly contributed to De Broglie’s Theory and acted as proof that particles and waves could overlap. Light can also be observed in the form of a particle called as a photon. When the light is seen on certain objects, the electrons are released. A Certain amount of energy is needed to eliminate an electron from the surface of an object. So, when a photon of greater energy than an electron hits a solid, an electron will be emitted.

When the electrons are emitted, they also release kinetic energy. According to classical wave theory, the greater is the intensity; greater is the energy. Because the energy of a wave is directly proportional to its amplitude, it was complex for scientists to find high intensity lights that did not affect its overall kinetic energy.

Researchers discovered that light frequency effectively changed the amount of kinetic energy. Since some objects do not emit electrons at particular frequencies, a threshold value V0 is applied. This threshold is used to describe the amount of kinetic energy required for a photon to eject an electron. The scientists arrived at a linear relation for frequency and kinetic energy and can be shown by the rough sketch below.

Wave Particle Duality

The slope of this line is known as Planck’s Constant, h = 6.63 x 10-34

Since the energy of waves and energy of light does not coincide, we can say that light is a particle that has the property of waves.

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Practise This Question

Equal charges q are placed at the four corners A,B,C,D of a square of length a. The magnitude of the force on the charge at B will be