Help with a review question please Test tomorrow

[caharris10]

Help with a review question please! Test tomorrow

Can you please help with this review question. My test is tomorrow and I am not sure how to do this.

Helium cation behaves like hydrogen atom. A particle with kinetic energy of 90.00 x 10^-12 erg collides with a gaseous helium cation in its ground state, quantum level n=1. After the collision, the kinetic energy of the particle is found to be 8.262 x 10^-12 erg. This event is followed by the Helium ion with the electron in quantum level n=? emitting light with a wavelength of 1214 angstroms when the electron drops to the quantum level n = 2. What is the energy of the electron in the ground electronic state, E1 of the helium atom?

 

[Drakkith]

Where exactly are you stuck? Please show your work you've done so far and post any applicable formulas or equations related to the problem.

 

[caharris10]

Well, here is where I am.

I know that

-E(emit)=E? - E2

-E photon = hc/λ

-E2 =( -21.79 x 10 ^-12) / 4

Does this mean that E(emit) is equal to hc/λ?

If so, then hc/λ = E? - ( -21.79 x 10 ^-12) / 4

I would then take this Energy found and find what quantum level corresponds to it.

If this is correct, what do I do next? And I might be wrong somewhere