# De Broglie Wavelength of Electron

• amcca064
In summary, the conversation discusses the calculation of the de Broglie wavelength for an electron with different kinetic energies and a photon with a specific energy. The equations used are E=hf, E=1/2*m*v^2, and *lambda*= Planck's constant / momentum. The participants also discuss the concept of wave-particle duality and its relevance to the de Broglie wavelength.

## Homework Statement

Ok, question is: " Calculate the de Broglie wavelength for an electron that has kinetic energy a)50.0 eV b) 50.0 keV and c) 3.00 eV d) What If? A photon has energy 3.00 eV. Find its wavelength.

## Homework Equations

E=hf

1/2 m(v^2)

*lambda* = Planck's constant / momentum

## The Attempt at a Solution

Was just going to use E = hf then find wavelength from f, but realized that v is unknown unless I can use classical equation K=1/2m(v^2) but I was not sure I can do this? If I can, problem is easy, if I can't... will need some help... Thanks!

You have the energy, what do you want to find v for? Use the Planck's constant with eV in it, and your units should work out.

Are you familiar with the De Broglie relationship, or are you studying in advance? ;-)

You need to use the final 2 equations you stated.

From E=1/2 * m * v^2

2E = m v^2
2Em = (m v)^2
2Em = p^2 p=momentum
p = (2Em) ^ 0.5
h/lambda = (2Em) ^0.5

Should be easy to find wavelength with the above equation.

mindscrape - don't need v, need v to find p, or at leaast i thought i needed it until I see that I can do what QuantumCrash suggests...

Was not sure if I could use de Broglie wavelength equation WITH Kinetic energy of a particle equation. i.e. Wasn't sure if i could consider electron particle AND wave in the same situationi. I thought maybe had to consider electron only as wave or only as particle depending on situation. But now I see can do both, Thanks for the help!

hahaha just realized that this is what de Broglie wavelength is all about anyways! wave-particle duality. wow, funny

## What is the De Broglie Wavelength of Electron?

The De Broglie Wavelength of Electron is the wavelength associated with an electron moving at a certain velocity. It is named after French physicist Louis de Broglie, who proposed that all particles, including electrons, exhibit wave-like properties.

## How is the De Broglie Wavelength of Electron calculated?

The De Broglie Wavelength of Electron can be calculated using the equation λ = h/mv, where λ is the wavelength, h is Planck's constant, m is the mass of the electron, and v is the velocity of the electron.

## What is the significance of the De Broglie Wavelength of Electron?

The De Broglie Wavelength of Electron played a crucial role in the development of quantum mechanics. It helped scientists understand the wave-particle duality of matter and provided evidence for the existence of subatomic particles.

## How does the De Broglie Wavelength of Electron relate to the Heisenberg Uncertainty Principle?

The De Broglie Wavelength of Electron is directly related to the Heisenberg Uncertainty Principle, which states that the position and momentum of a particle cannot be known simultaneously with absolute precision. The smaller the wavelength, the more uncertain the position of the electron becomes.

## Can the De Broglie Wavelength of Electron be observed in experiments?

Yes, the De Broglie Wavelength of Electron has been observed in various experiments, such as the Davisson-Germer experiment, which demonstrated the wave-like behavior of electrons. It is also used in technologies like electron microscopy, which relies on the wave nature of electrons.