Not my field, so I'll leave others to answer. But there's also further clumping. In light nuclei, nucleons are clustered as 4alpha particles (two protons and

Not my field, so I'll leave others to answer. But there's also further clumping. In light nuclei, nucleons are clustered as 4alpha particles (two protons and two neutrons). Simulation has ground-state 8Beryllium mass density shaped like a dumbbell of two alphas. And ground-state 20Neon shaped like a 10 femtometer ball-and-stick old wine bottle.[1] With a triangle of alphas (like non-ground-state C), a forth making a tetrahedron (like non-ground-state O), and the fifth hanging further out on the opposite side. Research for an old project. For improving introductory material science in early-primary school. Instead of the usual "just memorize the words - we don't teach those atoms things until the year after next", or the reform "teach atoms up", I was exploring "teach nucleons up". Atoms approached from the perspective of nuclei. Building out from the familiar, almost-classical marbles, rather than attempting to stand on a foundation of the least-intuitive utterly-bizarre wacky electrons. But I didn't manage to get much conversation/collaboration going.[2] :/ The traditional and common graphical representations of nuclei in education are very aphysical. [1] http://www.clarifyscience.info/assets/2017-Atoms/assets0/wk/1406.2473-Ne.png http://www.clarifyscience.info/assets/2017-Atoms/assets0/wk/... [small image] from https://arxiv.org/abs/1406.2473 https://arxiv.org/abs/1406.2473 page 4. https://arxiv.org/abs/1802.02873 https://arxiv.org/abs/1802.02873 is more recent, but only Ne. [2] http://www.clarifyscience.info/part/Atoms http://www.clarifyscience.info/part/Atoms is a crufty slowwwwwly-loading page (wasn't intended to be public), I wrote in support of a couple of exploratory conversations.