Question

Name a phenomenon or an experiment that proves;
i) Particle nature of the electromagnetic radiation
ii) Wave nature of particles.

Answer 1

Hint: Electromagnetic radiation is actually light having both the wave nature and particulate property. Electromagnetic radiation has both magnetic and electric fields. It was Bohr who proposed the dual nature of the particles. Electrons have both particles as well as wave nature.

Complete answer:
The particle nature of electromagnetic radiations is proven by the photoelectric effect. The photoelectric effect is that phenomenon when electromagnetic radiation is absorbed by the material and electrically charged particles are released within or from that material. This phenomenon explained that radiation consists of small packets of energy known as quanta and these energy packets or quanta are treated as particles.
The experiment that proves the wave nature of the electron particles is Davisson and Germer Experiment and they verified the de Broglie hypothesis. In this experiment, they show electrons exhibit diffraction when they are scattered from crystals in which nickel atoms are spaced appropriately. When the beam falls on the crystal, the atoms in the crystal scatter the electrons in all directions. These distracted rays are captured by a photographic plate and they form the pattern of concentric circular rays which discover the wave nature of the particles.

Note: Convincing evidence showing the particle nature of electromagnetic radiation was found in 1922 by Arthur Holly Compton, an American physicist when he was investigating the scattering of X-rays. De Broglie's hypothesis was the first to show that with every particle there is a wave associated with it.