Derivation of formula for orbital ranges in hydrogen atom

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SUMMARY

The discussion focuses on deriving the formula for orbital ranges in a hydrogen atom using angular momentum quantization and centripetal force equations. The key equation derived is r = k(q²)m/(n²ħ²), where k is Coulomb's constant, q is the charge of the electron/proton, m is the electron mass, and n is the principal quantum number. The participant identifies a flaw in reasoning regarding the relationship between radius and quantum number n, noting that the radius decreases with increasing n. The discussion emphasizes the need for clarity in distinguishing between linear and angular momentum.

PREREQUISITES
  • Understanding of quantum mechanics, specifically angular momentum quantization
  • Familiarity with classical mechanics, particularly centripetal force
  • Knowledge of electrostatics, including Coulomb's law
  • Basic calculus for manipulating equations
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  • Study the derivation of the Bohr model of the hydrogen atom
  • Learn about angular momentum in quantum mechanics
  • Explore the implications of quantum numbers on atomic structure
  • Investigate the relationship between force and potential energy in electrostatic systems
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Students of physics, particularly those studying quantum mechanics and atomic theory, as well as educators and researchers interested in the mathematical foundations of atomic models.

jjr
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I almost have the answer, I'm sure there's just a minor flaw in my reasoning. Here it goes:
We're given that the angular momentum of the atom is integer multiples of h-bar (n[itex]\hbar[/itex]) (integer depending on the orbit). Now the centripetal force is given by F = [itex]\frac{mv^2}{r}[/itex] = [itex]\frac{p^2}{mr}[/itex] = n^2[itex]\hbar[/itex]^2/mr where m is the electron mass, v is the velocity, p is the angular momentum and r is the range. This force equals the attractive coloumb force between the proton and electron, so: [itex]\frac{p^2}{mr}[/itex] = [itex]\frac{k(q^2)}{r^2}[/itex] => r = k(q^2)m/(n^2[itex]\hbar[/itex]^2) where k is coulombs constant, q is the charge of electron/proton.

The problem is obvious, seeing as how the radius drops with higher n's. The answer is in fact the reciprocal of the right part of the last equation. Can anyone spot my error?

Thanks, J
 
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Bump. If something is confusing, I'll be happy to elaborate
 
p=mv is linear momentum, not angular momentum.
 

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