TABLE OF CONTENTS:

PARTICLE NATURE OF LIGHT:

PARTICLE LIKE PROPERTIES OF LIGHT:

Particle like properties of light are

• Photoelectric effect
• Compton effect (Compton  scattering of X-rays).

The Phenomena  like photoelectric effect  and Compton effect etc. can be explained only in terms of quantum theory of light.(By assuming particle nature of light).

NEWTON’S CORPUSCULAR THEORY OF LIGHT: (1803)

Newton, proposed that light consists of tiny particles called corpuscles which are shot out at high speed by a luminous object.Newton’s theory of light seemed suitable to explain the straight-line casting of  sharp shadows of object placed in a light beam.

YOUNG’S DOUBLE SLIT EXPERIMENT: (1803)

The Newton’s corpuscular theory hypothesis failed when Young announced his double slit experiment of interference of light.

THOMSON’S DISCOVERY:

Thomson’s discovery of electron changed the way, and gave the electron its particle status.

BOHR’S QUANTUM THEORY OF LIGHT:(1913)

Bohr’s quantum theory, suggested  electron and proton are particles of matter.

EINSTEIN’S THEORY:

Einstein, stated that  a minimum energy necessary for  quantised  photons (of energy to eject photoelectron) with a kinetic energy of the photoelectrons  proportional to frequency of incident radiations.

PHOTOELECTRIC EFFECT: (1922)

The peculiarityby which electrons are emitted from certain metal surface, when sufficiently high frequency electromagnetic radiations are allowed to incident on it.

Whenever a unit of light called a photon hits the material it can create a photoelectron in the material which can be distinguished as an electric current flow.

COMPTON EFFECT: (1927)

Compton, observed electron is a particle, that  some parts of X-rays were scattered away from the beam direction with  longer wavelength than the incoming radiations.( electron  scattering experiment on crystalline structures,the electron behaves as a wave).

De BROGLIE’S DUAL NATURE:(1929)

De Broglie, suggested that light has a dual nature. It can behave as particles as well as waves.

CONFIRMATION OF de BROGLIE HYPOTHESIS OF MATTER WAVES.

DAVISSON AND GERMER EXPERIMENT: (1929)

Davisson and Germer, given the proof of confirmation of de Broglie hypothesis of matter waves.

NON-RELATIVISTIC WAVE EQUATION: (1933)

Schrodinger, discovered the non-relativistic wave equation for the electron wave mechanics.