This example problem demonstrates how to find the wavelength of a moving electron using de Broglie's equation. While an electron has properties of a particle, the de Broglie equation may be used to describe its wave properties.
Problem:
What is the wavelength of an electron moving at 5.31 x 106 m/sec?
Given: mass of electron = 9.11 x 10-31 kg
h = 6.626 x 10-34 J·s
Solution:
de Broglie's equation is
λ = h/mv
λ = 6.626 x 10-34 J·s/ 9.11 x 10-31 kg x 5.31 x 106 m/sec
λ = 6.626 x 10-34 J·s/4.84 x 10-24 kg·m/sec
λ = 1.37 x 10-10 m
λ = 1.37 Å
Answer:
The wavelength of an electron moving 5.31 x 106 m/sec is 1.37 x 10-10 m or 1.37 Å.