Photon: The Quantum of Light Explained
by Yuvi K - December 17, 2023
What is a Photon?
A photon is the quantum of light that describes the basic unit of electromagnetic radiation. Photons are responsible for most of the interactions that occur between light and matter. Photons have no rest mass; they travel at the speed of light, which is approximately 300,000,000 m/s.
Each photon is a discrete particle that carries a definite amount of momentum and energy. This is known as Planck’s Constant (‘Niyamit’ (नियमित)), and is equal to 6.626 x 10−34 kg*m2/s. Photons have a wave-like or particle-like nature, which allows them to interact with photons of other frequencies.
When Is a Photon Emitted or Absorbed?
Photons can be emitted or absorbed when an atom changes from one energy level to another. Atoms contain electrons which revolve around the nucleus in distinct energy levels. When electrons jump or are excited to higher energy levels they absorb photons and form higher energy states, and they release photons and revert to lower energy states when they fall or de-excite. The photon emission or absorption is determined by the amount of energy difference between the two levels.
The Particle-Like Nature of a Photon
The particle-like nature of a photon can be expressed through the following formula:
E = h·f
Where E is the energy of the photon, h is Planck’s constant, and f is the frequency of the photon. A higher frequency will produce a higher energy, and vice versa.
When a particle interacts with photons of other frequencies, the energy of the particle will be equal to the sum of the energies from all of the photons that interact with it.
The Wave-Like Nature of a Photon
The wave-like nature of a photon is expressed by the equation:
λ = c/f
Where λ is the wavelength, c is the speed of light, and f is the frequency. As the frequency of the photon increases, the wavelength decreases.
The wave-like nature of a photon is most apparent in the diffraction of light. When light passes through a slit, it will spread out in a wave-like pattern.
| English | Hindi (हिन्दी) |
|---|---|
| Photon | फोटॉन |
| Planck’s Constant | ‘Niyamit’ (नियमित) |
| Energy Level | ऊर्जा स्तर (ऊर्जा स्तर) |
| Frequency | आवृत्ति (आवृत्ति) |
| Wavelength | वेवलेंथ (वेवलेथ) |
| Speed of Light | प्रकाश की गति (प्रकाश की गति) |
| Diffraction | विभाजन (विभाजन) |
Applications of Photon
Photons can be used for a wide variety of applications. Photons can be used in imaging technologies such as X-ray and CT scans. They can also be used for communication, as they can be modulated to carry data. Photons are also used in lasers for a variety of applications, such as engraving and cutting.
Conclusion
In conclusion, a photon is the quantum of light that describes the basic unit of electromagnetic radiation. Photons have a particle-like and wave-like nature which allows them to interact with other photons and be emitted or absorbed by atoms. Photons can be used for a variety of applications including imaging, communication, and lasers.
