Question

The wavelength of an electron whose velocity is 1.7 x 104 m/s and whose mass is 9.1 x 10-28 g is __________ m.

Answer 1

The formula for DeBroglie wavelength is λ=h/p, where λ is the wavelength, h=6.626*10^-34 m₂ kg/s is the Planck's constant and p is the momentum of the electron. p=m*v, where m is the mass of the electron and v is the velocity of the electron.

First we need to calculate the momentum p:

m=9.1*10^-28 g=9.1*10^-31 kg because we need to plug in mass in kilograms

p=(9.1*10^-31)*(1.7*10^4)=1.547*10^-26 kg m/s

Now we calculate the wavelength:

λ=(6.626*10^-34)/(1.547*10^-26)=4.283*10^-8 m

So the DeBroglie wavelength of the electron is λ=4.283*10^-8 m.