Elements in the history of the Periodic Table.
Discovery of the Periodic Table was rendered possible only after four decisive prerequisites had been achieved. These were (i) the abandonment of the metaphysical and occult notions of elements that typified the alchemical era; (ii) the adoption of a modern and workable definition of an element; (iii) the development of analytical chemical techniques for the isolation of the elements and determination of their properties; and (iv) the devising of a means of associating each element with a characteristic natural number. The Periodic Table made its appearance on cue almost as soon as these preconditions had been fulfilled.
The Last Sorcerers: The Path from Alchemy to the Periodic Table
1 Front Matter 2 1. The Four Elements 3 2. Prelude tothe Birth of Chemistry 4 3. The Sceptical Chymist 5 4. The Discovery of the Elements 6 5. The Nail for the Coffin 7 6. a /Only an Instant to Cut Off That Heada 8 7. The Atom 9 8. Problems with Atoms 10 9. The Periodic Law 11 10. Deciphering the Atom 12 Epilogue: The Continuing Search 13 Appendix A: A Catalog of the Elements 14 Further Reading 15 Index
Differential Equations for Half‐Off‐Shell Matrix Elements
A first‐order differential equation is found for the quasiphase parameter which describes the half‐off‐shell scattering matrix. The quasiphase is given as Δ(∞), where Δ(r) obeys an equation involving the potential but not the wavefunction and Δ(0) = 0. The equation is used to develop low‐momentum expansions for Δ, and to derive upper and lower bounds for the expansion parameters.