Quantum Chemistry 1.5 - Bohr Hydrogen Model 2: Energy

Short lecture on the Bohr hydrogen model energy.

Bohr assumed the electron in the hydrogen atom travels in a fixed circular orbit with quantized angular momentum. By balancing the Coulomb force and centrifugal force acting on the electron, we can derive the radii, velocities, and energies of its allowed orbits. Transitions between these allowed energy levels leads to an expression which is in nearly exact agreement with the Rydberg formula, giving a value of the Rydberg constant which has extremely low error (~0.001%).

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[wardelllindsay]

The Fine Structure Constant
Copyright 2022 Wardell Lindsay.

I developed the accuracy of Alpha and improves the value of alpha = 7.2E--3 !

The velocity on electron is v= 7.2E-3x3E8=2.16E6 m/s !

[chrisagc]

Why when calculating the potential energy described by the coulomb force includes only r (and not r^2, as when describing it as coulomb force=centrifugal force) Wasn't the potential E described just as the Coulomb force?

[LeeCheYu]

Should the n2 & n1 in the ΔE equation be flipped according to how it's written?

[katharinasch]

Hello! First: thank you for these beautiful explanations!
In this video, which values do you insert for permittivity of free space, the elementary charge, and the mass of the electron? I know you can look these values up, but I get confused with the units at this point. Do I get the right numbers by constantly using the SI-units? And what is the permitivity in SI-units?

[awwhistorian]

When did we assume the mass of the proton was infinite? We never even mentioned the mass of the proton until this video. Personally I assumed the mass of the proton was the mass of the proton. The same way you would use assume the mass of the earth was a finite number in a earth-moon system. Any explanations would be greatly appreciated. Thank you for these videos!

[CC-sbix]

i could not understand 3:18 at all, where you get 8 from and if you divide both side by 2 why you still have two there

[awwhistorian]

There is no explanation for why Bohr chose v= h_bar*n. Did he pull it out of his grandpa's sock drawer or what? There must've been a reason for why he chose to use both Planck's constant and 2pi. Most textbooks also seem to skip over of this key step in the process. Doesn't seem very scientific to simply trust someone else's decision without being provided some form of explanation or thought process for why they assumed this.

[andreipaulau]

Hi! Thanks for the awesome videos :)

I have a question about the reduced mass. Why is it used here? During the whole derivation, we consider only the the Coulomb interactions and we concentrate on the forces acting on the electron, thus it seems that we just have to consider its mass. So if the proton is suddenly not infinitely heavy, why do we solve the problem that way and how does it work?

[sheriffabubakar]

Please where did u get the value of RH

[khalededbey]

Hi, Is there any notes to download instead of videos?