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University Quantum Mechanics I

University Quantum Mechanics I · Introduction to Three-Dimensional Quantum Mechanics · 14.09

Quantum numbers: which condition produces each label

Azimuthal single-valuedness fixes m, polar regularity fixes l of at least |m|, and normalisability at both ends of the half-line fixes a radial index that the nodes of u count.

Course-map guide · not a complete lesson or simulation

Scope & orientation

What this subsection covers

Azimuthal single-valuedness fixes m, polar regularity fixes l of at least |m|, and normalisability at both ends of the half-line fixes a radial index that the nodes of u count.

A strong response uses effective-potential curves for each l and states where the model stops being reliable.

Reasoning checklist

Evidence, assumptions and limits

01

Assumptions to state

State the system, observable, approximation, and conditions held fixed before using a model.

02

Evidence to collect

Does a spherical finite well always bind a state the way a one-dimensional well does, and how much deeper must it be before an l = 1 state appears?

Read the complete note

Does a spherical finite well always bind a state the way a one-dimensional well does, and how much deeper must it be before an l = 1 state appears? Useful evidence includes shot solutions u(r) started from u(0) = 0 with the small-r behaviour u ~ r(l+1) respected, eigenvalues located by node counting and sign changes, grid-spacing and cutoff convergence, binding thresholds for l = 0 and l = 1, and the 1D well for contrast.

03

Limits to state

This GioPhysics course map is an adaptable learning sequence, not academic credit, accreditation, or a universal university syllabus.

Read the complete note

This GioPhysics course map is an adaptable learning sequence, not academic credit, accreditation, or a universal university syllabus. It is a first dedicated quantum-mechanics course, distinct from University Physics V, which covers quantum mechanics alongside atomic, nuclear and particle physics in twenty units: this course is narrower, slower, and teaches the linear algebra it needs rather than assuming it. Hydrogen appears here as an introduction, with the full radial derivation belonging to a second course. A midterm examination is assumed around week 8. Follow your institution's published scope, notation, laboratory programme, and assessment rules. A result should be checked against units, signs, limiting cases, and the conditions under which its model was derived.

Diagram & examples

Work the claim before choosing an equation

Interactive concept map

Follow the model from claim to evidence.

01 · Physical claimQuantum numbers: which condition produces each label

Azimuthal single-valuedness fixes m, polar regularity fixes l of at least |m|, and normalisability at both ends of the half-line fixes a radial index that the nodes of u count.

Read the complete note

Azimuthal single-valuedness fixes m, polar regularity fixes l of at least |m|, and normalisability at both ends of the half-line fixes a radial index that the nodes of u count. Rotational symmetry alone gives the 2l+1 degeneracy in m for every central potential; spin would be a fourth label and is absent from this spinless treatment. Everything is now in place for hydrogen, where only V(r) changes.

02 · RepresentationThe subsection's claim

Model, evidence, and boundary

03 · TestPrediction before measurement

What is the strongest test of a claim about Quantum numbers: which condition produces each label?

04 · Evidence & boundaryDecide, then qualify

Does a spherical finite well always bind a state the way a one-dimensional well does, and how much deeper must it be before an l = 1 state appears?

Read the complete note

Does a spherical finite well always bind a state the way a one-dimensional well does, and how much deeper must it be before an l = 1 state appears? Useful evidence includes shot solutions u(r) started from u(0) = 0 with the small-r behaviour u ~ r(l+1) respected, eigenvalues located by node counting and sign changes, grid-spacing and cutoff convergence, binding thresholds for l = 0 and l = 1, and the 1D well for contrast.

Interactive diagram for Quantum numbers: which condition produces each label: follow the physical claim through its representation, proposed test, evidence, and model boundary.

modelModel, evidence, and boundary turns the stated idea into a representation that can make a prediction.

Example questions

Try the reasoning before revealing the structure.

Diagram check

What is the strongest test of a claim about Quantum numbers: which condition produces each label?

Quick check

Test the reasoning, not recall

What is the strongest test of a claim about Quantum numbers: which condition produces each label?

Choose an answer to test the model.