# Modern physics, imaginary particle

1. May 14, 2013

### Coolstorybro

1. The problem statement, all variables and given/known data
The energy level scheme for the mythical one-electron element crazyidium(the names not really relevant). The potential energy of an electron is taken to be zero at an infinite distance from the nucleus (a) How much energy does it take to ionize an electron from the ground state (b) A 15 eV photon is absorbed by the crazyidium atom, what are the possible wavelengths can be emitted photons have (c) what will happen if a photon with energy of 8eV strikes a crazyidium atom? why? (d) if photons emitted from crazyidium transitions n=4 to n=2 and from n=2 to n=1 will eject photoelectrons from an unknown metal, but the transition n=3 to n=2 will not, what are the limits (maximum and minimum possible values) of the work function of the metal (e) if a 40eV photon strikes the electron in the ground state what will be the deBroglie wavelength of the ejected electron. THIS ATOM IS NOT HYDROGEN!!!

2. Relevant equations
KE= E - $\phi$
KE=(1/2)mv2
h=pλ
E=hf
Me = 9.11x10-31
Mp = 1.67x10-27
E=pc
h=6.63x10-34 J(seconds)
or = 4.14x10-15eV(seconds)
e=1.6x10-19C
hc=1240eV(nm)

3. The attempt at a solution
My work is a mess, and this sheet is old so i can't exactly read it
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. May 15, 2013

### Staff: Mentor

Can't help much if I don't see the level scheme.

You seem to be missing the most important one: What is the equation for the energy levels of a hydrogenic atom?

3. May 15, 2013

### Coolstorybro

sorry
n=infinity___________ 0eV

n=4_______________-2eV
n=3_______________-5eV

n=2_______________-10eV

n=4_______________-20eV

I'm not sure what the equation is for the energy levels of a hydrogenic atom,

E=E(initial)(1/(n(initail)squared) + 1/(n(final)squared))

I'm not sure about that equation, i can't remember that equation or if thats the right one or not

4. May 16, 2013

### Staff: Mentor

Looks like you were aiming at the Rydberg formula for the energy of transitions:
$$\Delta E = h c R \left( \frac{1}{n_i^2} - \frac{1}{n_f^2} \right)$$
with $R$ the Rydberg constant. But since the energy of all levels all already given in the problem, you actually don't need that equation.

That level scheme contains all the information need to solve the problem. You'll have to be more specific as to where you have problems.

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