Question

State de Broglie hypothesis.

Answer 1

Louis de Broglie, in 1924, stated that a wave is associated with a moving particle (i.e. matter) and so named these waves as matter waves. He proposed that just like light has dual nature, electrons also have wave like properties.
Wavelength of a moving particle is given by $\lambda =\frac{h}{p}$
where $h$ is the Planck's constant and $p$ is the momentum of moving particle.