ToughSTEM
ToughSTEM
A question answer community on a mission
to share Solutions for all STEM major Problems.
Cant find a problem on ToughSTEM?
0
(a) What is the wavelength of a 7.0-eV photon? (b) What is the de Broglie wavelength of a 7.0-eV electron?
Edit
Community
1
Comment
Solutions
0
Energy=Plank's constant*c/Wavelength

Energy=7*1.602 E-19 in joules
c=3E8 m/s
h=Plank's constant=6.626 E-34

Now, wavelength=hc/E=1.77 E -7 meters = 177 nm (ultraviolet)

For DeBroglie,

Wavelength=h/momentum=h/mv

at these energies (7ev) we don't need to correct for relativistic mass, so...

momentum=p=mv=square root (2m*Kinetic Energy)

mass=9.109 E -31kg,

so Deb wavelength=4.64 E-10 meters = .464 nm
Edit
Community
1
Comment
Close

Choose An Image
or
Get image from URL
GO
Close
Back
Close
What URL would you like to link?
GO
α
β
γ
δ
ϵ
ε
η
ϑ
λ
μ
π
ρ
σ
τ
φ
ψ
ω
Γ
Δ
Θ
Λ
Π
Σ
Φ
Ω
Copied to Clipboard

to interact with the community. (That's part of how we ensure only good content gets on ToughSTEM)
OR
OR
ToughSTEM is completely free, and its staying that way. Students pay way too much already.
Almost done!