Wave Nature of Light-Dual Nature of Matter

Newton performed experiments with prisms and lenses and demonstrated that the white light has the combined individual colour of the rainbow. These optics findings are termed by Newton as a ‘corpuscular’ view of light. 

According to Newton’s law of motion, the light is composed of streams of extremely tiny particles that can travel at a high speed. A wave is a periodic movement or oscillation that can easily transport energy from one space point to another. The wave nature of light means that light can behave as an electromagnetic wave. In quantum mechanics, wave-particle duality is an important chapter. The dual nature of matter and radiation is comparatively a discovery. A matter can have a wave nature or particle nature. To prove the dual nature of matter theory various experiments were conducted later.

Important concepts of Wave Nature of Light -Dual Nature of Matter

Few necessary topics regarding this concept are the following:

Minimum energy is required for emitting an electron in Electronic Emission from a metal’s house. By following the below methods electronic emission is supplied to the free electrons:

• By the Thermionic emission method, suitable heating enables the electrons to emerge out of the metal.
• In the Field emission method, the electron emission gets influenced by a powerful electric field to emerge out of the metal.
• Photoelectric emission is a method where the light’s appropriate frequency helps in electrons emission by illuminating the surface of the metal. The emitted electrons of photogeneration are known as photoelectrons.

What is the Photoelectric Effect?

The photoelectric effect phenomenon requires the  electrons that can escape from the material’s surface. This material surface consists of both positive ions as well as negative ions. As the metal surface is hit by the light,  few electrons present near absorb energy of the surface from the radiation of the incident  and gradually overcome the positive ion’s attraction. After that, the electrons get enough energy to escape out of the surface of the metal into the adjoining. This process is known as the photoelectric effect.

Few facts and terms related to the photoelectric effect:

• Threshold Frequency: The frequency of light of the threshold frequency is maximum that forces an photoelectron to emit from a metal surface.
• Work Function: This minimum energy is required to eject an electron from a metal’s surface.
• Threshold Wavelength: This is known as the maximum wavelength of light that ejects a photoelectron from the metal’s surface.
• The cut-off is the retarding potential or minimum negative that is denoted by V0, where the value of  photoelectric current will become zero. This is also known as stopping potential.
• The incident light intensity effect falling is direct  with the photoelectric current for a fixed frequency of incident.

Photoelectric Effect: Laws

The laws associated with the Photoelectric effect is discussed below:

• The Photoelectric effect is proportional directly to the incident power of the light on a given metal surface and also the incident light frequency.
• The frequency threshold exists for a specified metal. In this definite least  frequency, the emission of photo-electric is absent.
• The maximum kinetic energy  level of the photoelectrons is dependent on the incident light frequency.
• The photoelectric process is instantaneous.

Different Theories on the Dual Nature of Matter

De Broglie Hypothesis

In the De Broglie hypothesis, he defined the relation between wavelength and momentum.

Planck’s Quantum Theory

This theory explains that when we apply heat to a black body, this will lead to thermal radiation emission with various frequencies or wavelengths.

An Experiment conducted by Davisson and Germer 

This experiment proves the electron’s wave nature as well as verifies the equation of de Broglie and it resulted in establishing the first proof based on an experiment on the mechanics of quantum. The parts that are involved in this experiment are the following:

Electrostatic Particle Accelerator: To accelerate the electrons two contradictory charged plates are needed to be employed and this process is called potential.

Electron Gun: This is a Tungsten filament emitting electrons through thermionic emission.

Collimator: The accelerator that has a narrow beam is tied within a cylinder for the electron together with its axis.

Target: Target is a Ni crystal where the beam of the electron is ejected. To catch the electrons that are separated from the Ni crystal, detectors are used.

Conclusion

On a concluding note, in this article, we have learned about the concept of the wave nature of light and the dual nature of matter. A wave is a periodic movement or oscillation that can easily transport energy from one space point to another. The wave nature of light means that light can behave as an electromagnetic wave. Wave-particle duality is a chapter in quantum mechanics. The dual nature of matter and radiation is comparatively a discovery. Along with this in this article, we have also learned about the concept of the photoelectric effect and a few facts and terms related to the photoelectric effect.