Photon emitted when proton changes state

[wahaj]

Homework Statement

a proton is confined in an infinitely high square well of length 10 fm. If the proton transitions from n=2 to ground state determine the energy and wavelength of the photon emitted

Homework Equations

E = \frac{h^2 n^2}{8mL^2}
E = \frac{hc}{\lambda} \ \ or \ \ \lambda = \frac{hc}{E}

The Attempt at a Solution

I need some one to tell me if I did this right.
energy at n = 2
E_1 = \frac{(6.626E-34)^2( 2^2) }{8(1.67E-27)(1E-14)^2}
E_1 = 1.31E-12

energy at ground state
E_0 = \frac { (6.626E-34)^2}{8(1.67E-27)(1E-14)^2 }
E_0 = 3.286E-13

energy of photon released
E = E_1 - E_0
E = 9.859E-13 \ J

wavelength of photon
\lambda = \frac{(6.626E-34)(3E8)}{9.859E-13}
\lambda = 2.016E-13 m = 0.2016 pm
this would be a gamma ray.

So did I do this question right?

 

[mfb]

There are some units missing, but a gamma ray is the right order of magnitude for such a photon and the approach looks fine. You can check the calculations with WolframAlpha, for example.

 

[wahaj]

thanks.