CHEM101 Lecture Notes - Lecture 1: Elementary Particle, Unified Atomic Mass Unit
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CHEM101 Full Course Notes
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There is a common saying: what in the world is not chemistry? . Developments of the fundamental chemical laws and the atomic theory what in the world isn"t chemistry: democritus (460 370 bc) first proposed matter was made up of indivisible particles atoms (greek atomos, which means uncuttable ) In the late 18th century: law of conservation of mass matter is neither created nor destroyed, law of constant composition a given sample of compound always contains the same fraction of the element by mass. For example: in calcium carbonate, % of ca = 40%, c = 12%, o = 48% For 1 g of c, o = 1. 33 g. For 1 g of c, o = 2. 66 g. For example: for carbon dioxide, c = 27. 3%, o = 72. 7% 72. 7 g of o 2. 66 g of o. 27. 3 g of c 1 g of c. Thus, for 1 g of c, o = 2. 66 g.