Is the Principal Quantum Number n the Same as Planck's Proposed Quantization?

[asdf1]

was the principal quantum number proposed by Planck?
i remember that Planck proposed quantization, n, but is that the same thing as the principal quantum number n? the principal quantum number represents the quantization of energy, right?

 

[El Hombre Invisible]

To my knowledge, Bohr proposed the principal quantum number in all but name (the same symbol n was used). However, Bohr was incorrect about what it was he thought was being quantised and why. It was remarkable, then, that his theory was so accurate (e.g. at predicting spectral lines).

 

[asdf1]

so it has nothing do with Planck?

 

[El Hombre Invisible]

Well, Planck introduced the idea that electromagnetic radiation consists of integer numbers of 'quanta' of energy E = hf. But he did not apply it to atoms. He used it to derive a new equipartition theory that showed that frequencies of radiation from a source hit a peak then fall off very quickly.

Bohr was the first to semi-succesfully apply quantisation to the atom AFAIK. The idea of quantum numbers and quantum states is introduced by Schrödinger's model of the atom. But the primary quantum number does correspond well with Bohr's n.

Bohr's n is the quantisation of angular momentum. This is a quantised quantity in Schrödinger's model, but as a consequence of more fundamental laws. This quantisation in Bohr's model was conjectured, not derived.

n in Schrödinger's model essentially labels the wavefunction and its associated energy level. Basically the quantisation of total energy plus or minus a few extra bits.

 

[asdf1]

wow~ thank you very much! :)