Acknowledgements The support of the Foundation for Chemical Research, Inc. is gratefully acknowledged. This conclusion to our 40-year effort to understand the origin of the Solar System and its elements would not have been possible without moral support and encouragement from the late Professors Glenn T. Seaborg and Raymond L. Bislinghoff.

Figure Captions (Click on Figure titles to reach the Figures)

Figure 1. The solar system formed out of the debris of a single supernova (SN) and the Sun formed on its collapsed core^1-11. This explains the data in Figs. 2-5.

Figure 2. Combined ²⁴⁴Pu/¹³⁶Xe and ^238,235U/^206,207Pb age dating shows that the supernova (SN) exploded about 5 billion years ago¹².

Figure 3. ²⁶Al/²⁶Mg age dating shows that condensation began almost immediately, trapping high values of ²⁶Al/²⁷Al in SiC and in graphite grains of meteorites within 1-10 million years (0.001-0.010 billion years) of the supernova¹³. Grains that started to condense earlier grew larger, like fallout particles from nuclear weapons. They also trapped elements before complete mixing of isotopes made in various SN layers. These isotopic anomalies are illustrated in Figure 5.

Figure 4. Primordial He and Ne from the outer SN layers were trapped in carbon-rich meteorite grains with excess ¹³⁶Xe (on the right). Isotopically "normal" Xe came from the interior of the star where fusion had destroyed light elements like He and Ne (on the left). The r-process made excess ¹³⁶Xe in the outer stellar layers where He and Ne remained. Shown here are data for mineral separates of the Allende meteorite. The linkage of primordial He and Ne with excess ¹³⁶Xe is observed in all types of meteorites⁴ and in the He-rich atmosphere of Jupiter¹⁰.

Figure 5. The isotopic anomaly patterns of numerous elements show excesses and deficits of the same isotope in different meteorite grains^5,9,11. These elements display "mirror-image" isotopic anomaly patterns because elements of normal isotopic composition are mixtures of the isotopically anomalous components made in different SN layers. This illustrates the isotopic anomaly patterns observed in three elements with seven stable isotopes, Ba, Nd and Sm.

Figure 6. The lighter isotopes, m_L, are enriched by a factor, f, relative to heavier isotopes, m_H, in the solar wind, where f = (m_H/m_L)^4.56. H leaking from the Sun’s interior preferentially carries lighter particles to the solar surface^14-16.

Figure 7.After correcting for the mass-fractionation shown in Figure 6, the most abundant elements in the bulk Sun are Fe, Ni, O, Si, S, Mg and Ca^14-17. In 1917 Harkins¹⁹ reported that these same, even-Z elements comprise 99% of meteorites.

Figure 8. Fractionation-corrected solar abundances are linked to nuclear stability¹⁷, as suggested by Harkins¹⁹ in 1917, except for a large excess of H leaking from the Sun’s interior. This figure is published in Ref. 17 and 20.

Figure 9. This plot of mass per nucleon, M/A, vs. charge per nucleon, Z/A, for all stable and long-lived nuclides shows that ¹H has both the highest potential energy (M/A) and the highest charge density (Z/A). By contrast, ⁵⁶Fe has the lowest potential energy (M/A) and an ordinary value of Z/A (charge density). First published in a report²⁰ to FCR, Inc., this figure is reproduced in Ref. 17.

Figure 11. A 3-D plot of ground state nuclides shows the "cradle" as a function of atomic number, Z. The isotopes of each element, represented by slices through the cradle at constant Z, define mass parabolas that are related by the capture or emission of neutrons. First published here, this figure is reproduced in Ref. 21.

Figure 12. Least-square lines fit to the parabolas at each value of A (Fig. 10) are used to estimate potential energy per nucleon for isobars, from Z/A = 0 (Z,A = 0,A) to Z/A = 1 (Z,A = A,A). The data in Fig. 11 can also be used to estimate the potential energy of isotopes from Z/A = 1 (Z,A = Z,Z) to Z/A @ 0 (Z,A = Z,infinity), a very massive nucleus composed completely of neutrons, except for the Z protons.

Figure 13. The "cradle" from Figure 12 predicts values of M/A when the charge density is zero, Z/A = 0, for odd values of A = 1-263. First published here, this figure is reproduced in Ref. 22.

Figure 14. The potential energy of particles in a neutron star can be estimated by extrapolating values of M/A at Z/A = 0 from Figure 12 to a neutron star at 1/A @ 0. The "best fit" line through all values of A yields an intercept at 1/A = 0 suggesting that these particles will have @ 10 MeV more energy that the free neutron. First published here, this figure is reproduced in Ref. 22.

Figure 15. The potential energy of particles in a neutron star can be estimated by considering only A > 150 and extrapolating values of M/A at Z/A = 0 from Figure 12 to a neutron star at 1/A @ 0. The intercept of this "best fit" line at 1/A = 0 suggests that these particles will have @ 22 MeV more energy that the free neutron. First published here, this figure is reproduced in Ref. 22.

Figure 16. Nuclear reactions that generate the Sun’s luminosity and the excess ¹H shown in Figure 8. The energy generated by reactions 1a, 1b and 1c can be represented by vertical transmissions between the lines in Figure 15. The emission and decay of neutrons may contribute to the luminosity of isolated neutron stars²⁴. The flux of solar neutrinos²⁵ confirms that reactions 1c and 2c, H-fusion, generate only part of the Sun’s total radiant energy.