# Formula: De Broglie wavelength Mass    Velocity

## De Broglie wavelength

Unit
Every particle of mass $$m$$ (e.g. electron, proton) can be assigned a wavelength $$\lambda$$ in quantum mechanics, the so-called matter wavelength (also called De-Broglie wavelength). De-Broglie wavelength determines the interference ability of particles.

Here $$m \, v$$ is the momentum $$p$$ of the particle.

## Mass

Unit
Mass of the particle. Heavy particles have a shorter matter wavelength than light particles.

## Velocity

Unit
Velocity with which the considered particle moves. Fast particles have a shorter matter wavelength than slow particles.

## Planck's Constant

Unit
Planck's constant is a physical constant (of quantum mechanics) and has the value: $$h = 6.626 \, 070 \, 15 \,\cdot\, 10^{-34} \, \mathrm{Js}$$

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