Excitation energy of helium

  • Thread starter pivoxa15
  • Start date
2,234
1
What is the excitation energy of the He atom?

I imagine this is also the energy of the photon released by the electron as it deexcites from the p orbital to the s orbital.

I guess this would be different to ionisation energy as that refers to taking the electron away completely from the atom.

Is it explained here with 9 different excitation levels?
http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/atspect.html

It looks like going from 1s to 2p recquires 21eV. But from this graph
http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/atspect.html
it looks like the excitation energies are around 2.5eV corresponging to around 500nm wavelength photons. Is that because they only showed excitations not from 1s but from 2s and above? In fact the excitation from 1s would recquire 21eV or more corresponding to a photon of wavelength in the ultaviolet range so can't be seen. The site lists ones that can be seen so can't be the 21eV photons.
 
Last edited:

DrClaude

Mentor
6,858
2,987

Want to reply to this thread?

"Excitation energy of helium" You must log in or register to reply here.

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving

Hot Threads

Top