Question

Which of the following has the largest de Broglie wavelength assuming that the velocity is the same for all?

• A. $C{O}_2$ molecule
• B. $N{H}_3$ molecule
• C. electron
• D. proton

Answer 1

The correct option is C electron

According to de Broglie equation,
$\lambda =\frac{h}{mv}$
where $\lambda$, $v$, $h$ and $m$ are wavelength, velocity, Planck's constant and mass of a particle respectively.

As velocity is the same for all the particles/molecules.
$\lambda$ $\propto$$\frac{1}{m}$
$\therefore$ As the mass of the electron is least, so the electron has the largest wavelength.