State de-Broglie hypothesis.

Explanation

De Broglie hypthesis : In 1924, Louis de Broglie proposed that the wave-particle duality may not be unique to light but a universal charactristic of nature, so that a particle of matter in motion also has wave or periodicity associated with it which becomes evident when the magnitude of Planck's constant h cannot be ignored.
De Broglie equation : A particle of mass m moving with a speed v will, under suitable experimental conditions, exhibit the characteristics of wave of wavelength `lambda` given by
`lambda=(h)/(mv)=(h)/(p)`
where `p=mv-=` magnitude of the momentum of the particle.
Thsi ralation is called the de Broglie equation, and the wavelength `lambda` associated with a particle momentum is called its de Broglie wavelength. The corresponding waves are termed as matter waves.