Wave nature of electromagnetic radiations: -
First explanation gives by James Maxwell (1870)
1) Oscillating magnetic & electric fields produced by the oscillating charged particles are perpendicular to each other and both also perpendicular to the wave direction of propagation.
2) These waves do not require medium i.e. electromagnetic wave can travel in vacuum.
3) Electromagnetic radiation differs from one another in frequency or wavelength gives electromagnetic spectrum.
4) Different units are used to represent electromagnetic radiation.
n = frequency,
l = wavelength.
Particle nature of electromagnetic radiation :-Also known as Planck’s Quantum theory
=> Planck suggested that the atoms and molecules can absorb or emit energy in discrete quantities nit in continuous manner. Planck gives it name as quantum. Energy (E) of quantum of radiation is directly proportional to its frequency(n)
Where, h = planks constant = 6.626× 10-34 js