Development of the periodic table Original Scenario-Based Download PDF

Questions

1. 1.

   In an alternate-history archive, a celestial scholar unearths an elemental chart where tellurium and iodine are inverted because elements were sorted strictly by increasing atomic mass. A companion journal notes that true periodic harmony is restored only when elements are arranged by the fundamental positive charge of their atomic nuclei rather than total mass. The scholar learns that an Earth physicist verified this ordering by bombarding metallic targets with cathode rays to record their emission spectra. Which historical breakthrough correctly identifies this scientist and the experimental evidence that established the modern periodic table?

   • A) Dmitri Mendeleev organized elements into octaves based on thermal conductivity measurements.
   • B) John Newlands established the periodic law by averaging atomic weights within repeating chemical triads.
   • C) Johann Döbereiner determined atomic numbers by analyzing the backscattering angles of alpha particles.
   • D) Henry Moseley established atomic numbers as the organizing basis by analyzing the frequencies of characteristic X-rays.