Excited hydrogen

[Ice-cream]

hey can any1 confirm my answer?

 

A hydrogen atom in its ground state absorbs a proton of wavelength 121.5nm. To which higher energy state will it be excited?

(a) n=2 (b) n=3 © n=4 (d) n=5

 

(the answer i got was n = 1.15 so roughly n= 1, using bohr's equation and E = hc/wavelength. but that doesn't match any of the multiple choice answers on the worksheet. wat do u guys think?)

[mezarashi]

This depends on what level the electron was on. The lowest level it can be in is n=1, so if it has enough energy to jump 1 level, then obviously the answer is (a) n = 2. 1+1 = 2.

 

My own calculations show that the photon gave 10.216 eV of energy to the electron, thus allowing it to jump from n=1 to n=2. n=1 (-13.6eV), n= 2 (-3.4eV) a difference of 10.2 eV. Note that at 0eV, the electron is free from the nucleus (conduction band).

[Dave]

The question says that the electon is in its ground state.

[swansont]

I agree with Mez. 10.2 eV, which is the jump to the n=2 state.

[Ice-cream]

thanx guys, i realised wat i did wrong (i used n=0 for ground state lolz)