# Formula De Broglie wavelength Mass Velocity

## De Broglie wavelength

`\( \lambda \)`Unit

`\( \mathrm{m} \)`

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

`\( m \)`Unit

`\( \mathrm{kg} \)`

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

## Velocity

`\( v \)`Unit

`\( \frac{\mathrm m}{\mathrm s} \)`

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

## Planck's constant

`\( h \)`Unit

`\( \mathrm{Js} \)`

Planck's constant is a physical constant (of quantum mechanics) and has the value:

`$$ h = 6.626 \, 070 \, 15 \,\cdot\, 10^{-34} \, \mathrm{Js} $$`