What is the Correct Formula for Calculating Angular Momentum in Bohr's Theory?

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Discussion Overview

The discussion revolves around the calculation of angular momentum for an electron in a 3d orbital, particularly within the context of Bohr's theory versus Schrödinger's theory. Participants explore the implications of different models on angular momentum values and the conditions under which these values apply.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant presents a formula for angular momentum in a 3d orbital as sqrt(2(2+1)) * h / (2 * π), suggesting it should apply universally.
  • Another participant proposes an alternative value for angular momentum in an excited hydrogen atom, stating it can also be expressed as 3 * h / (2 * π), raising questions about the consistency of angular momentum values.
  • Some participants argue that the Bohr model does not accurately describe angular momentum, highlighting its limitations compared to quantum mechanical models.
  • A participant questions the logic of comparing results from the Bohr model, which is deemed incorrect, with results derived from the Schrödinger equation, which is considered correct.
  • There is a discussion about the energy levels of subshells in hydrogen-like species, with a claim that energy levels of 3s and 3d should be equal, leading to a query about the corresponding angular momentum.
  • One participant expresses uncertainty about which formula to use for calculating angular momentum, debating between Bohr's formula and the Schrödinger formula, which is presented as sqrt(l(l+1)) * h / (2 * π).

Areas of Agreement / Disagreement

Participants do not reach a consensus on the correct formula for calculating angular momentum, with multiple competing views on the applicability of Bohr's model versus Schrödinger's model. The discussion remains unresolved regarding the correct approach to take.

Contextual Notes

Participants note the limitations of the Bohr model in explaining angular momentum and its discrepancies with quantum mechanics, but do not resolve the implications of these limitations on the calculations being discussed.

vkash
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what is angular momentum of a electron in 3d orbital.
Answer 1: d=2 angular momentum = sqrt(2(2+1))* h/2*pie

If this answer is correct then it should correct for all the conditions.so see second answer.
Answer 2: what if i say that was excited hydrogen piece then it's angular momentum can also be written as 3*h/2*pie

Both the answer are not same what is wrong. How angular momentum of one electron has two values?
 
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The Bohr model of the atom doesn't give the correct angular momentum.
 
alxm said:
The Bohr model of the atom doesn't give the correct angular momentum.

I was expecting for such answer i have a reply for you that is in hydrogen like species energy of all the sub shells in a shell is equal so energy of 3d should equal to 3s then what will new angular momentum in 3s.
One more thing is always try to answer question with logic. without proper logic your answer is not useful.
One thing coming in my mind as it's solution is that, Is there any thing like d orbital for hydrogen like species.
 
vkash said:
in hydrogen like species energy of all the sub shells in a shell is equal so energy of 3d should equal to 3s then what will new angular momentum in 3s.

I'm not sure what you're asking here. If you solve the Schödinger equation for the hydrogenic atom, the boundary conditions give you solutions for integer n = 1,2,3.. quantum numbers for the linear momentum, and l quantum numbers (such that 0 <= l <= n - 1) for the angular momentum, such that the states are 2l+1 degenerate. Those values of the linear momentum define a shell, those for angular momentum define a sub-shell. 3d is n=3, l=2 and 3s is n=3, l=0. If you're asking what n=3, l=1 is, then that's the 3p shell.
One more thing is always try to answer question with logic. without proper logic your answer is not useful. One thing coming in my mind as it's solution is that, Is there any thing like d orbital for hydrogen like species.
In the standard Bohr model, electronic states only have angular momentum, and incorrect values of it. It doesn't explain the degeneracy, or magnetic quantum number, or spin, or the fine and hyperfine interactions and many other things, it's also fundamentally at odds with real quantum mechanics; it's a semi-classical theory. The Bohr model is entirely incorrect in its physical description, it just happens to give the correct energy levels for the shells.

So where's the logic in comparing the results of theory known to be incorrect with the results derived from the theory that's known to be correct? The concept of 'orbitals' comes from the solutions to the Schrödinger equation for a hydrogenic atom, not the Bohr model.
 
I want to say that if an electron is in 3d orbital in hydrogen like species then what is it's angular momentum? Which formula should i use Bohr's formula for Schrödinger formula. A we know in hydrogen like species energy of 3s,3p,3d is equal so angular momentum should also equal.
From two replies it is coming as answer that Bohr's model is wrong for giving angular momentum and i should use this shrodinger formula (sqrt(l(l+1))* h/2*pie) to find angular momentum. (l is azimuthal quantum number.)
thanks for replying.
 

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