Question

Name a phenomenon or an experiment which proves:
(i) Particle nature of electromagnetic radiations.
(ii) Wave nature of particles.
(Description of phenomenon/experiment is not required)

Answer 1

Hint: Electromagnetic radiation (EM radiation or EMR) refers to the waves of the electromagnetic field, propagating (radiating) through space, carrying electromagnetic radiant energy. It includes radio waves, microwaves, infrared, (visible) light, ultraviolet, X-rays, and gamma rays. Electromagnetic radiation has a dual nature: wave properties and particulate (photon) properties. So, we need to mention the phenomena which help in proving the dual nature of EM waves.

Complete step by step answer:
(i) Particle nature of electromagnetic radiations:
According to Planck's quantum theory, Different atoms and molecules can emit or absorb energy in discrete quantities only. The smallest amount of energy that can be emitted or absorbed in the form of electromagnetic radiation is known as quantum.
So, to study the quantum or particle nature of EM waves, we have a phenomenon named a Photoelectric effect. The effect is often defined as the ejection of electrons from a metal plate when light falls on it.
(ii) Wave nature of particles.
As an electromagnetic wave, it has both electric and magnetic field components, which synchronously oscillate perpendicular to each other and perpendicular to the direction of energy and wave propagation.
The Davisson-Germer experiment demonstrated the wave nature of the electron.

Note:
Light has both wave-like and particle-like properties (wave-particle duality), but only shows one or the other, depending on the kind of experiment we perform. A wave-type experiment shows the wave nature, and a particle-type experiment shows particle nature. One cannot test the wave and the particle nature at the same time.