What Frequency Photon Ionizes an Atom from n=2 State?

[sskk221]

Homework Statement

The following diagram represents the allowed electronic energy levels of a hypothetical atom. What frequency photon would be required to ionize this atom if it were already in the n = 2 state?

[PLAIN]http://img32.imageshack.us/img32/667/picture2vt.png

Homework Equations

E = hf

The Attempt at a Solution

Ionizing the atom would require emission of a photon. From the picure, E = 4eV for an emission of a photon:

4eV = hf
f= 9.65e14 Hz but this is not the answer. Any suggestions??

 

[rock.freak667]

You used the correct formula. Did you change eV to J? That is the only way I could see you getting it wrong.

 

[sskk221]

yeah I did 4eV*1.6e-19 to convert it to Joules. Then I divided by Planck's constant to get the frequency. This problem seems so easy, but I'm missing something... :\

 

[ehild]

What does ionization mean? What is the energy of the electron when the atom is ionized?

ehild