Riddle: Where is Epsilon in Bohr Model of Atom?

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Discussion Overview

The discussion revolves around the Bohr model of the atom, specifically addressing the role of the constant epsilon in the energy formula for electrons in orbit and its absence in the formula for emitted photons. Participants explore the implications of this discrepancy and the units involved.

Discussion Character

  • Technical explanation
  • Debate/contested

Main Points Raised

  • The original poster (OP) notes a formula for the total energy of an electron in orbit that includes epsilon, but questions why it is absent in the photon emission formula.
  • Some participants request clarification on the book being referenced, seeking the title and author for context.
  • One participant suggests that the formula is in terms of the nth Bohr radius, indicating that epsilon may not be needed in certain unit systems.
  • Another participant expresses uncertainty about the units of the equation, pointing out a perceived missing electron mass.
  • There is a suggestion that the units being used might set epsilon to 1, which is debated by others who believe it might still be relevant.
  • One participant insists that in their institution, SI units are always used, implying that the absence of epsilon is problematic.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the role of epsilon in the formulas discussed. There are competing views on whether it is necessary and how the units affect the equations.

Contextual Notes

There are unresolved questions regarding the assumptions made about the units and the specific context of the formulas presented in the book referenced by the OP.

AhmedHesham
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Hi curious people
Today i had a lecture about bohr model of the atom .we know that the total energy of electron in orbit is minus e squared divided by 8 pi times epsilon times R of the orbit . this is written in my book and i agree with this .But when the author writes a formula for an emitted photon he writes the difference of the law mentioned above but without epsilon . why ?
Thankes
 
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AhmedHesham said:
this is written in my book

Which book?
 
PeterDonis said:
Which book?

His book! He just said so! :wink:

OP, we're looking for the book's title, and author, and if you can do a good job, maybe a scan of that page. If not, please write the entire formula.
 
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This is a picture from the book
 

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haushofer said:
We are curious, not psychics.
There is no such thing as psychic.
- Patrick Jane
 
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I have no idea what units the equation you posted is supposed to be in. There's a missing electron mass, for one thing.
 
Vanadium 50 said:
I have no idea what units the equation you posted is supposed to be in. There's a missing electron mass, for one thing.

No, it's not missing. This formula is in terms of the ##n^{th}## Bohr radius ##r_n##, which is given by:

##r_n = \dfrac{n^2 \hbar^2}{Z e^2 m_e}##

(where ##Z## is the number of protons in the nucleus, and ##m_e## is the mass of the electron)

The answer to the original poster's question is that they are using units where ##\epsilon_0 = 1##.
 
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Ah...it's buried in the r's. I see,
 
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stevendaryl said:
he answer to the original poster's question is that they are using units where .

Are you sure? Isn't it buried in the r's as well?
 
  • #11
No ...i think it is missing
We always us SI in my institute
 

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