The key difference between photon and electron is that photon is a packet of energy while the electron is a mass.
An electron is a subatomic particle that plays a vital role in almost everything. The photon is a conceptual packet of energy, which is very important in quantum mechanics. Electron and photon are two concepts that developed greatly with the development of quantum mechanics. It is vital to have a proper understanding of these concepts, to understand the field of quantum mechanics, classical mechanics and related fields properly.
CONTENTS
1. Overview and Key Difference
2. What is Photon
3. What is Electron
4. Side by Side Comparison – Photon vs Electron in Tabular Form
5. Summary
What is Photon?
Photon is a topic that we discuss in wave mechanics. In quantum theory, we can observe that waves also have particle properties. The photon is the particle of the wave. It is a fixed amount of energy depending only on the frequency of the wave. We can give the energy of the photon by the equation E = hf, where E is the energy of the photon, h is the Plank constant, and f is the frequency of the wave.
Figure 01: Movement of a Photon as Electromagnetic Radiation
We can consider photons as packets of energy. With the development of relativity, scientists discovered that waves also have a mass. It is because waves behave as particles on interactions with matter. However, the rest mass of a photon is zero. When a photon is moving with the speed of light, it has a relativistic mass of E/C2, where E is the energy of the photon and C is the speed of light in a vacuum.
What is Electron?
An atom consists of a nucleus that has a positive charge, and it contains almost all of the mass and electrons orbiting around the nucleus. These electrons have a negative charge, and they contain a very small amount of mass compared to the nucleus. An electron has a rest mass of 9.11 x 10-31 kilograms.
The electron falls into the subatomic particle family fermions. Moreover, they have half-integer values as spin. The spin is a property describing the angular momentum of the electron. The classical theory of electron described the electron as a particle orbiting around the nucleus. However, with the development of quantum mechanics, we can see that the electron also can behave as a wave.
Figure 02: Electron (in red) and Atomic Nucleus (in blue) in a Hydrogen Atom
Further, the electron has specific energy levels. Now, we can define the orbit of the electron as the probability function of finding the electron around the nucleus. Scientists conclude that electron behaves as both a wave and a particle. When we consider a travelling electron, some of the wave properties become prominent than the particle properties. When we consider the interactions, particle properties are more prominent than the wave properties. The electron has a charge of – 1.602 x 10-19 C. It is the smallest amount of charge any system can obtain. Moreover, all other charges are multiplications of the unit charge of the electron.
What is the Difference Between Photon and Electron?
Photon is a type of elementary particle which acts as a carrier of energy, but the electron is a subatomic particle which occurs in all the atoms. The key difference between photon and electron is that the photon is a packet of energy while the electron is a mass. Moreover, the photon does not have a rest mass, but an electron has a rest mass. As another significant difference between photon and electron, the photon can go at the speed of light, but for an electron, it is theoretically impossible to obtain the speed of light.
Moreover, a further difference between photon and electron is that the photon displays more wave properties whereas the electron displays more particle properties. Below is an infographic on the difference between photon and electron.
Summary – Photon vs Electron
Photon is an elementary particle, and we can describe it as a packet of energy while the electron is a subatomic particle having a mass. Therefore, we can say that the key difference between photon and electron is that the photon is a packet of energy while the electron is a mass.
Reference:
1. Jones, Andrew Zimmerman. “What Is a Photon in Physics?” ThoughtCo, Sep. 3, 2018. Available here
2. Britannica, The Editors of Encyclopaedia. “Photon.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 7 Feb. 2018. Available here
Image Courtesy:
1.”The Photon”By Illusterati (CC BY-SA 3.0) via Commons Wikimedia
2.”2750576″ by sjeiti (CC0) via pixabay