Wavelength, emission spectrum, electron transitions

AI Thread Summary
The discussion focuses on calculating the wavelength of the emission spectrum for the He+ ion during an electron transition from n = 3 to n = 1. The user initially applied the Rydberg equation for hydrogen, resulting in a wavelength of 102.6 nm, which aligns with the Lyman series. However, the correct wavelength for He+ is 25.6 nm, as the Rydberg constant must be adjusted for the ion's +2 charge due to its additional protons. Participants emphasize the need to use the modified Rydberg equation specific to He+. Understanding the derivation of the Rydberg constant for He+ is crucial for accurate calculations.
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Homework Statement



Determine the wavelength (in nm, to one decimal place) of the line in the emission spectrum of the He+ ion produced by a transition from n = 3 to n = 1.

Homework Equations


I used the Rydberg equation for this, although I'm not sure it is the correct one to use.
fa7bd92080914c973a88453a20c0c730.png



The Attempt at a Solution


Plugging in n1=1 and n2=3, I get an answer of 102.6nm. A search on wikipedia for the Lyman series also shows that transition from n=3 to n=1 is 102.6nm.

The solution given, however, is 25.6nm. Obviously I am not understanding the question. Help would be appreciated.
 
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The Rydberg constant will be different for He+ than for hydrogen because He+ has more protons in its nucleus.
 
The equation you used is for Hydrogen. The He ion has a charge of +2, so the Rydberg constant is modified. Go back and look up the equation for how this Rydberg constant is derived.
 
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