de Broglie Equation Definition

Chemistry Glossary Definition of de Broglie Equation

electrons
The de Broglie equation describes the wave properties of electrons. Science Photo Library/MEHAU KULYK/Getty Images
by Anne Marie Helmenstine, Ph.D.
Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels.
Updated July 11, 2018

In 1924, Louis de Broglie presented his research thesis, in which he proposed electrons have properties of both waves and particles, like light. He rearranged the terms of the Plank-Einstein relation to apply to all types of matter.

de Broglie Equation Definition

The de Broglie equation is an equation used to describe the wave properties of matter, specifically, the wave nature of the electron:​

λ = h/mv,

where λ is wavelength, h is Planck's constant, m is the mass of a particle, moving at a velocity v.
de Broglie suggested that particles can exhibit properties of waves.

The de Broglie hypothesis was verified when matter waves were observed in George Paget Thomson's cathode ray diffraction experiment and the Davisson-Germer experiment, which specifically applied to electrons. Since then, the de Broglie equation has been shown to apply to elementary particles, neutral atoms, and molecules.