Quantum mechanics

[DennisG]

An electron in the hydrogen atom makes a transition from an energy state of principle quantum number N(i) to the N=2 state. If the photon emitted has a wavelength of 434 nm, what is the value of N(i)?

....no idea

[cepheid]

An electron in the hydrogen atom makes a transition from an energy state of principle quantum number N(i) to the N=2 state. If the photon emitted has a wavelength of 434 nm, what is the value of N(i)?

....no idea

Hmm...my guess is that you determine the photon energy using the relation

E = \frac{hc}{\lambda}

Then you look up how large an energy transition (in "steps" of N) down to N = 2 is required for a photon of that energy to be emitted.

If I've made a mistake, someone please tell me.

[Tide]

An electron in the hydrogen atom makes a transition from an energy state of principle quantum number N(i) to the N=2 state. If the photon emitted has a wavelength of 434 nm, what is the value of N(i)?

....no idea

Does the term "Balmer Series" ring a bell?