According to Albert Einstein, electromagnetic energy is contained in quanta or packets, often referred to as photons.

In accordance with the earlier observations, the wavelength of light had a huge impact on the electrons that were ejected. Additionally, the intensity of light directly affects the electrons that are released. This is a sign of its particle-like nature previously thought to be a wave.

What exactly is the particle nature of light?

Before 1900, physicists believed that light travels through waves. However, the photoelectric effect experiment showed that light contains energy packets. Additionally, other forms of electromagnetic energy include the energy quanta.

“Photons” as we know them now are nothing more than packets of energy. Photons are energy-rich packets.

Examples of photons

• The sun transforms particles into light, and heat takes the form of photons.
• An electromagnetic carrier

This, in turn, aids in determining how light particles behave.

Additionally, 

• Light sources that have longer wavelengths have lower energy. This is mainly the case with the wavelengths of orange and red.

• Contrary to what you might think, shorter wavelengths are filled with more photons or energy packets.

• Thus, wavelengths with more energy content have displaced the freest electrons off the metal surface.

This particular observation helped Planck discover that the intensity of a lighting source is directly related to the radiation of these electrons.

What is the wave-particle duality?

Light is composed of photons or quantum of energy that gives it a particle-like nature. However, it can also be found in the form of waves.

Young’s double-slit experiment

In the double-slit experiment of Young, electrons were pushed through the double-slit. This resulted in conclusive evidence of the wave nature of light.

In the end, Young’s double-slit experiment proved the concept of ‘light’s dual nature’.

So, it is possible to recall the well-known phrase “light isn’t just an oscillation but also particles.” This is a reference to the duality of waves and particles as it is referred to today. Therefore, a photon has the properties of both particles and waves. 

Waves are prominent when viewed in the context of the propagation of light. In addition, photons play an essential role in the electromagnetic transmission of energy.

So, light is wave-particle duality.

The de-Broglie’s dual nature of light

In the dual nature of the light theory of de Broglie, it displays wave properties like dispersion and interference when it is in motion. Simultaneously, when it’s stationary, it displays light particle properties. De Broglie’s wavelength affirmed that matter has a dual nature.

The relationship between the properties of particle and wave is also outlined in de Broglie’s relationship.’

Based on de Broglie’s equation, light displays “wave-like” and “particle-like” properties.

E= hv ,

 p= hc/λ

here, c = velocity of light

v = frequency

h = Planck constant = 6.627× 10-34 Js

E = energy 

λ = de-Broglie wavelength of light

What are the characteristics of Photons?

The most well-known properties of photons are the following:

• Theoretically, photons are the smallest form of electromagnetic radiation or energy. Thus, they form the primary component of light.
•   “c” signifies it in mathematical terms. Additionally, it has an acceleration of 2.99 x 108 ms-¹. In addition, it is not active, which means it is always moving. However, photons are only able to travel in space with this velocity.  
• The energy of a photon is similar to that of the frequency of oscillation at the source of light and Planck’s constant. So, E = hv where “v” refers to frequency. The word ‘h’ in this equation is the constant of Planck, which is 6.62607004 x 10-34 Js. It is also possible to express it in terms of E = hv = hc/λ, in which λ represents = wavelength.
• The formula for the momentum of a photon will be p= hc/λ.
• It’s stable and does not have any electric charge.
• If a photon collides with other subatomic particles such as electrons, the resulting phenomenon is known by “the Compton effect.” Additionally, collisions are able to conserve energy as well as momentum. Thus, you could describe it as an elastic collision, which preserves energy and momentum.
• It is also theoretically non-massive. However, these quantum particles transmit energy only in collisions between other particles.
• In the absence of space, photons are able to travel through space at the rate of light.

Photoelectric Effect

In this case, when electromagnetic radiation (such as light) strikes a surface (such as metal), the emission of electrons occurs. 

In the photoelectric phenomenon, when it is not high enough, there are no electrons observed to be freed. However, if the frequency is sufficiently high, it is possible for some electrons to be seen.

These observations confirm that.

• Light is composed of particles.
• The intensity of the particle grows in proportion to the frequency.
• Each particle provides energy to only one electron.

Conclusion

Alongside the nature of light as a wave, the photoelectric effect experiment led to a different phenomenon. It was suggested that light, when in contact with matter, behaves in a way made of energy packets or quanta. Quanta, or energy packets, are referred to as photons in the present. This particular experiment led to a new theory, known as “The Particle Nature of Light”.

• Light is a particle. The intensity and wavelength of light exert a certain influence on the electrons that are ejected.
• Alongside the nature of light as a wave, the photoelectric effect experiment resulted in a second bizarre phenomenon.
• Photons, also referred to as energy packets or light quantum, can be described as elementary particles.
• In the simplest sense, the definition of a photon is that it is a light-based particle.
• Photons are the fundamental component of light, regarded as the smallest quantum radiation.