CHM 101 1st Edition Lecture 1Outline of Current Lecture I. MatterII. MeasurementIII. Classifications of MatterIV. Dimensional AnalysisV. Scientific NotationCurrent LectureMatter & Measurements- Chemistryo Study of matter and the changes it undergoes- Mattero Anything that has mass and occupies space- Changes in matter can be physical and chemicalo Examples: Physical- ice melting Chemical-metal rusting- Visualizing Chemistryo Macroscale- things we can see with the naked eyeo Nanoscale-the scale on which atoms exist- Chemistry provides nanoscale explanations of macroscale matter- Solid- has a definite shape, definite volume, not compressible- Liquid-indefinite shape, definite volume, not compressible- Gas-indefinite shape, indefinite volume, compressibleClassification of Matter- Pure substance-matter that has a fixed composition and a characteristic set of propertieso Element-substance that cannot be decomposed into simpler substances. An element’s basic unit is an atomo Compound-a chemical combination of two or more elements A compound’s basic unit is a molecule- Example- pure water H2Oo Exception: some elements are diatomic H2, N2, O2, F2, Cl2, Br2, I2- Mixture- a physical combination of two or more pure substances o Homogeneous mixture-substances are unevenly distributed throughout the mixture Example-muddy water, orange juice and pulpo Homogeneous mixture-substances are evenly distributed throughoutDimentional Analysis- Tool that is used to keep track of units when doing conversionso Conversions Numerator and denominator equal to each other Example: 1in=2.54cm-1∈¿ 2.54 cm Example problem: If your height is 66in what is it in centimeters?- 66in * 2.54 cm = 168cm1in- Cross the inches out and multiply 2.54cm by 66in to get your answer- Like measurements are always diagonal from each otherScientific Notation - Simpler way of writing numbers when dealing with several decimal places or zeroso Example- 3350g = 3.35 * 103 Move the decimal until there are no zeros left in the notation, unless the zero is between two significant
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