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)
i.e.
E=hn
Where, h =
planks constant = 6.626× 10-34 js