Undergrad Riddle: Where is Epsilon in Bohr Model of Atom?

[AhmedHesham]

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

 

[PeterDonis]

this is written in my book

Which book?

 

[haushofer]

We are curious, not psychics.

 

[Vanadium 50]

Which book?

His book! He just said so!

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.

 

[AhmedHesham]

This is a picture from the book

 

[Demystifier]

We are curious, not psychics.

There is no such thing as psychic.
- Patrick Jane

 

[Vanadium 50]

I have no idea what units the equation you posted is supposed to be in. There's a missing electron mass, for one thing.

 

[stevendaryl]

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 $\epsilon_0 = 1$.

 

[Vanadium 50]

Ah...it's buried in the r's. I see,

 

[Vanadium 50]

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?

 

[AhmedHesham]

No ...i think it is missing
We always us SI in my institute