1. Education
You can opt-out at any time. Please refer to our privacy policy for contact information.

Discuss in my forum

de Broglie Example Problem

Finding the Wavelength of a Moving Particle

By

It's not hard to calculate wavelength if you know how to use the de Broglie equation.

It's not hard to calculate wavelength if you know how to use the de Broglie equation.

Justin Lewis, Getty Images
This example problem demonstrates how to find the wavelength of a moving electron using de Broglie's equation.

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.

©2014 About.com. All rights reserved.