- #1

chef99

- 75

- 4

## Homework Statement

Compare and contrast a 2.2 eV photon with a 2.2 eV electron in terms of wavelength (m).[/B]

## Homework Equations

p = h/λ

λ = h/mv

## The Attempt at a Solution

For photon:

p = h/λ

λ = h/p

λ = (6.63 x10

^{-34}) / (1.17 x10

^{-27}kgm/s)**

λ = 5.67 x10

^{-7}m

**I have already determined the momentum as is just one part of the question, in which the energy, momentum, rest mass and velocities are calculated.

For electron:

λ = h/mv

λ = (6.63 x10

^{-34}) / (9.11 x10

^{-31}kg)(8.8 x10

^{5}m/s)

λ = 8.27 x10

^{-10}m

I am confident in my answers, I am just curious as to why the wavelength for the electron is smaller than that of the photon, as I would have assumed the wavelength of the photon would be smaller, due to its greater velocity. I thought smaller wavelength means a higher frequency, which, in turn, means the wave is moving faster? However, this cannot be the case as the photon is obviously moving faster. I'd appreciate any explanation as I haven't been able to find one. This is, of course, assuming I've done my calculations correctly but I think I have. Thanks