Question
Explain de Broglie’s equation.
✓
Answer
de Broglie's equation:
[Note: According to de Broglie's equation, the wavelength of a moving particle is inversely proportional to its mass. Therefore, heavier particles have much smaller wavelength than lighter particles like electrons.]
- de Broglie proposed (in 1924) that matter should exhibit a dual behaviour. That is, every object which possesses a mass and velocity behaves both as a particle and as a wave. An electron has mass and velocity. This means that an electron should have momentum ( $p$ ), a property of particle as well as wavelength $(\lambda)$, a property of wave.
- According to de Broglie, the wavelength $\lambda$ of a particle of mass $m$ moving with a velocity $v$ is $\lambda=\frac{\mathrm{h}}{\mathrm{mv}}$ where, $\mathrm{h}$ is Planck's constant.
- The quantity mv gives the momentum of the particles. $\lambda=\frac{\mathrm{h}}{\mathrm{p}}$ where, $\mathrm{p}$ represents the momentum of the particle.
- de Broglie's prediction was confirmed by diffraction experiments (a wave property).
[Note: According to de Broglie's equation, the wavelength of a moving particle is inversely proportional to its mass. Therefore, heavier particles have much smaller wavelength than lighter particles like electrons.]
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