de-Broglie’s hypothesis

de-Broglie in his study, assuming that what is true with energy ( X- ray/light ) is also true with matter, as they are interchangeable according to Einstein’s theory of relativity, put forward an hypothesis stating that “ Since nature loves symmetry, if the radiation behaves as particle under certain circumstances, then one can even expect that entities which ordinarily behaves as particles to exhibit properties attributable to only waves under appropriate circumstances”.
This hypothesis is known as de-Broglie hypothesis.
de-Broglie went on to prove that λ = h/p, where h is Planck’s constant and p is momentum of the particle/ wave. λ is the wave length, known as de-Broglie wavelength.