CHEM 1110 Lecture 2: Atomic Theory
28 Aug 2016
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Individuals: democritus - greek philosopher (460-370 bc): matter is made of tiny indivisible particles (atomos meaning indivisible, john dalton (1766-1844 ce) - starting to combine and mix elements together to run various reactions. Observed and constructed a set of postulates for atomic theory of matter based off of empirical data: 1. Elements are composed of small particles called atoms: atoms of an element are identical to one another. (now we know this is. Wrong: chemical reactions rearrange atoms, but do not alter them, compounds are formed by combining atoms in xed integer ratios. You either have an atom or you don"t. Experiments to show not all atoms are identical: cathode ray tube (1897) If you applied the voltage to the anode (positively charged electrode, a ray would come out and light up the end of the tube: these rays weren"t light. (knew it wasn"t light.
