# Chem

posted by
**Anonymous**
.

Hello

What is the wavelength (in nm) of the line in the spectrum of the hydrogen atom that arises from the transition of the electron from the orbital with n =5 to the orbital with n = 2?

Note, the line corresponds to the energy of the photon that is emitted in the transition.

Find the de Broglie wavelength (in nm) associated with an electron that is moving with a velocity of 5330 km/s. The electron rest mass is 9.11 x 10-31 kg.

Note, electrons having this speed would need to be treated as waves in atoms because the wavelength is on the order of the size of atoms.

I'm not really sure how to do either of them, so if you could help me it would be great! Thanks in advance! :)