These questions are starting to piss me off....anyways
Cobalt-60 is a radioactive isotope used to treat cancers of the brain and other tissues. A gamma ray emitted by an atom of this isotope has an energy of 1.33 MeV (million electron volts; 1 eV = 1.602e-19 J). What is the frequency (in Hz) and wavelength (in m) of this gamma ray?
I used the equation E=HC/lambda (E is energy, H is Plank's constant, 6.63e-34, C is the speed of light, 3.0e8, and lambda is the wavelength.) I solved for lambda and got HC/E=lambda. Plug and chug and I get 1.2e-6m. Only problem is, that's not the correct answer. So what am I doing wrong?
Edit: Okay. First problem was that I didn't convert 1.33 MeV to J. So I re-did the calculations with 2.13066e-19J and came out with 9.3e-7m and that's still wrong. So my question still stands.