Atoms and the stuff of the world

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How we learned what matter is made of: Dalton's atoms, Avogadro's molecules, Mendeleev's periodic order — and then the atom coming apart, with Thomson's electron, Rutherford's nucleus, and Chadwick's neutron, on the eve of the quantum theory that would finally explain it. The chemistry that turns out to be the low-energy face of quantum mechanics.

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Explain what Dalton's atomic theory actually claimed and what evidence forced it.Read the periodic table as a consequence of atomic structure, not a lookup table.Recount how the atom went from "indivisible" to nucleus-plus-electrons in twenty years.Say why Perrin's Brownian-motion measurements ended the debate over whether atoms are real.

resources

○The Disappearing Spoon— Sam Keananchor · book
○Stuff Matters— Mark Miodownikcompanion · book
○A Short History of Nearly Everything— Bill Brysoncompanion · book
○Understanding Physics, Vol. 3: The Electron, Proton, and Neutron— Isaac Asimovoptional · book

sessions

unlocks The Light unit (an atom's spectral colours) and the entire Quantum path — the atom is what quantum mechanics was invented to explain. Einstein's 1905 Brownian-motion paper, read in the Light unit, is the proof the atom is real.

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