How Does the Zeeman Effect Alter the Wavelength of Hydrogen's Paschen Lines?

AI Thread Summary
The discussion focuses on the calculation of wavelength changes for the 4p to 3d transitions in hydrogen's Paschen lines under a 2T magnetic field, utilizing the Zeeman effect. The participant initially grapples with an incorrect result of 0.01m, which is far too large for the expected near-infrared wavelengths around 800 nm. After identifying a calculator error related to the product "hc," they confirm that their approach is fundamentally correct. The importance of remembering the value of hc (1240 eV-nm) for quicker energy-wavelength conversions in quantum mechanics is emphasized. The conversation concludes with a commitment to include this constant in their formula sheet for future reference.
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Homework Statement


The \alpha lines of Paschen in the hydrogen spectrum are due to transitions n=4 \to n=3. Identify the allowed 4p \to 3d transitions and determine the change in wavelength for each transition if there's an external B field of 2T.

Homework Equations


\Delta E=m_l \mu _B B.
E=\frac{hc}{\lambda}.

The Attempt at a Solution


I graphed all transitions possible (it's an enormous mess).
Now say I want to calculate the difference of wavelength of with and without the magnetic field for the transition 4p, m=0 and 3d, m=1 (it's allowed). I have that m_l=1.
So applying the first formula I gave, this gives \Delta E \approx 1.85 \times 10^{-23}J=1.16\times 10^{-4}eV.
Applying the second formula this gives me \Delta \lambda \approx 0.01 m.
I know this result is totally senseless. It's way too big, enormous. From memory Paschen lines are in the near infrared so about 800 nm and a bit up. Nothing like 0.01m!
I really don't know what I'm doing wrong.
I would appreciate some help.
 
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Nevermind, the approach is right. I just made a calculator mistake with the product "hc".
 
Hi! Glad it worked out.

By the way, both eV energy units and the product hc comes up so frequently in quantum mechanics that it's a good idea to remember (or right down, wherever you have a list of physics constants) it's value:

hc = 1240. eV-nm​

The energy-wavelength conversions will go quicker that way.
 
Redbelly98 said:
Hi! Glad it worked out.

By the way, both eV energy units and the product hc comes up so frequently in quantum mechanics that it's a good idea to remember (or right down, wherever you have a list of physics constants) it's value:

hc = 1240. eV-nm​

The energy-wavelength conversions will go quicker that way.

Thank you for your concern. And yes, I agree with you, I'll get "hc" in eV*nm into my formula sheet.
 
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