## anonymous one year ago FAN AND MEDAL 1. In which of the following cases is the wavelength of the emitted radiation greatest? Electron jumps from third orbit to second orbit. Electron jumps from third orbit to first orbit. Electron jumps from fourth orbit to first orbit. Electron jumps from fifth orbit to second orbit.

1. Michele_Laino

when electron makes a transition, between state with energy Ei to another state with energy Ef, the frequency \nu of the emitted or absorbed photon is: $\Large h\nu = Ef - Ei$

2. Michele_Laino

more precisely: $\Large h\nu = \left| {Ef - Ei} \right|$

3. Michele_Laino

since we have considered the case of absorption of a photon

4. Michele_Laino

now we have: $\Large \nu = \frac{c}{\lambda }$ so we can write: $\Large \frac{{hc}}{\lambda } = \left| {Ef - Ei} \right|$ or: $\Large \lambda = \frac{{hc}}{{\left| {Ef - Ei} \right|}}$

5. Michele_Laino

now the greatest wavelength corresponds to the smallest energy change

6. Michele_Laino

and the smallest energy change, happens when electron jumps the smallest number of levels

7. anonymous

Electron jumps from fourth orbit to first orbit.

8. Michele_Laino

no, since the electron makes three transitions

9. Michele_Laino

I think when electron makes only one transition, do you see that option?

10. Michele_Laino

for example in the first option the electron goes from the third level to the second one

11. anonymous

12. Michele_Laino

so it makes only one transition, right?

13. anonymous

yeah

14. Michele_Laino

therefore it is the first option