1. Chapter 1 The Foundations of Chemistry HW27Qs: 3, 4, 6, 10, 14,18, 20, 26, 28, 30, 32, 34, 36, 38, 40, 44, 46, 50, 54, 56, 58, 60, 62, 64, 66, 68,70 Dr. Shiunchin C. Wang
2. 1.1 Matter and Energy CHEMISTRY MATTER What is Chemistry? Chemistry is the science that describe matter regarding with its composition, structure, properties. matter is anything has mass and occupies space . Mass Occupies Space + Mass is a measurement of the quantity of matter in a sample of any materials. Mass is different from weight. Mass does not vary in different place, but weight does. Weight : a measurement of the gravitational attraction of the earth for the body. Volume: a 3-D space. Subdiscipline of chemistry: Analytical, Biological, Biophysical, Inorganic, Organic, Material, Physical, Polymer, Nanotechnology etc.
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5. 1.1 Matter and Energy (Cont.) Law of Conservation of Energy : Energy cannot be created or destroyed in a chemical reaction or in a physical change. It can only be converted from one form to another . Relationship between matter and energy by Albert Einstein in 1940: E= mc 2 Exothermic reaction : convert chemical energy into heat energy. Endothermic reaction : heat, light, and electrical energy can be converted into chemical energy
8. Non-Mixtures: Elements Atom: smallest particle of an element. Atoms consists 3 fundamental particles: electrons, protons, neutrons.
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13. Significant Figures (p 23) Determination of 123,000 significant figures: (1) 1.23 x 10 5 has 3 significant figures, (2) 1.230 x 10 5 has 4 significant figures. Special case: 24 0 000 has 3 significant figures. Therefore, it is best to use “scientific notation” to represent the significant figures. In this case will be 2.40 X 10 5 . Note: Measurement of volumetric cylinder by reading the bottom of the meniscus . Significant Figures = Exact numbers + 1 estimate number