## Abstract

The proposed structures of stable nuclei of H-1 through C-13 incorporate an alternating up and down quark sequence (AQS) of equally spaced quarks around regular geometries. AQS nuclear models represent quark positions in the same way molecular ball and stick models represent the relative positions of atoms. In AQS, the ball identifies the center of quark mass and the stick length is constant and equal to the most recent radius of the proton (0.8414 fm). AQS radius predictions use current quark masses, and predictions for H-1 to C-13 demonstrate 99.3% average agreement (SD 4%) and statistical correlation of ρ = 0.96, p<0.001, with accepted RMS charge radii. These results compare favorably to a close-packed nucleons model and a spherical nucleus model. A set of AQS parameters is included. Light nuclei tend to form ring structures corresponding to regular polyhedra, the smallest of which is the dodecagon structure of helium-4. Opposite quarks link nucleons to maintain a continuous sequence of alternating equally spaced quarks. Quark sequences may overlap so that protons overlap with neutrons. The more regular polyhedron structures of light nuclei yield better AQS radius predictions, whereas larger nuclei tend to be less regular and are thus less predictable (with the exception of the double overlapping octadecagon structure for the 36 quarks of C-12). The relative certainty in the accepted radius of helium-4, and its geometric relationship to the proton radius, allow a geometric solution to the “proton puzzle” yielding an AQS prediction for the proton radius of 0.8673±0.0014 fm.

## Version notes

Version number 2 includes structures for B-9 through C-13.