Mercury energy levels

[fredrick]

[IMG]http://img75.imageshack.us/img75/8945/38369221rm3.png[/img]
[IMG]http://img75.imageshack.us/img75/38369221rm3.png/1/w325.png[/img]
Calculate the momentum of the photon of highest possible enrgy level emitted from these level of mercury.

This might be stupid but I can calcualte the momentum no probs, the problem is how to work out the highest possible energy of the photon. The answers have from the (n=1) to the (n=2) state the highest photon is emitted. But if its emitted wouldnt it be from the (n=2) to the (n=1) state not the other way round?? And why cant it be from the (n=1) to the (n=4) state? Im comfused :idiot2:

[cara.mel]

What is the exact question?

The answer is probably saying n=1 to n=2 because first of all you need to give it energy to get it up into n=2. But the fact the answer doesnt have 4-1 either means its a dodgy question or I don't have the full question here to read.

[fredrick]

The question before it says, calculate the wavelength of the photon of highest possible energy emitted from these levels of mercury. No other infomation is given

[fredrick]

This is there answer:
The photon of highest possible enrgy will be the one which emits the highest energy photon, and this occurs when the enrgy gap between levels is largest.
Thus E=4.9eV=4.9X(1.6E-19)j...
E=hf...
 

[cara.mel]

dodgy question then, n=2 -> n=1 isn't the largest transition