The de Broglie equation applies to:

The Davisson and Germer experiment showed that:

If the velocities of hydrogen $(H_2)$ and helium $(He)$ molecules are equal,then the ratio of the wavelengths of helium to hydrogen is .......

Calculate the de Broglie wavelength of a $CO_2$ molecule moving with a velocity of $440 \, m/s$. (Molar mass of $CO_2 = 44 \, g/mol$)

The de Broglie wavelength of a tennis ball of $60 \ g$ moving with a velocity of $10 \ m/s$ is approximately

$A$ ball weighing $25 \ g$ moves with a velocity of $6.6 \times 10^4 \ cm/sec$. Find the associated de Broglie wavelength.