Question

Give three characteristics of photons.

Answer 1

Hintdefine what a photon is, explain its behaviour, give details such as its energy, mass, stability, momentum, charge, etc.

 Complete step-by-step solution:Photon, in the simple language, can be defined as the basic unit of all light. They are minute packets of energy or quantum of energy which constitute the electromagnetic waves.
Photons are always in motion and in the vacuum, travel at a constant speed of$2.998 \times {10^8}m{\sec ^{ - 1}}$.
This is the speed of the light and it is denoted by the letter$c$. Einstein proved that light is the flow of photons.
The basic properties of photons are:
$(1)$ They have zero mass and zero rest energy. They only exist as the moving particles.
$(2)$They have no electric charge.
$(3)$ In the empty space, they travel at the speed of light.
$(4)$ Photon is the stable particle.
$(5)$ Photon cannot decay on its own.
$(6)$ Energy of photons can be transferred during interaction with other particles.
$(7)$ Symbol used for photons is$\gamma $.
$(8)$ Energy of photons depends on the frequency and wavelength. It is directly proportional to the frequency and inversely to the wavelength.
Energy$ = h\nu $
Where$h$is the Planck constant.
$\nu $ is the frequency
Or we can write the relation as:
$E = \dfrac{{h\nu }}{\lambda }$
$c$ is the speed of light

Note:- This is a complete concept based question. You must be acquainted with important characteristics of elementary particles. In this given problem, we have used the terms like rest mass and rest energy. These are mass and energy when the particle has zero velocity.