1. CHAPTER 1* Introduction: Matter and Measurement Suh Kwon

2. 1.1 – The Study of Chemistry  The Molecular Perspective of Chemistry Matter = physical material of the universe that has mass and occupies space Element = substance that cannot be separated into simpler substances by chemical means Atom = almost infinitesimally small building blocks of matter Molecules = chemical combination of two ore more atoms

3. 1.2 – Classifications of Matter  States of Matter SolidLiquidGas Both a definite shape and a definite volume Distinct volume independent of its container but has no specific shape No fixed volume or shape; conforms to the volume or shape of its container Rigid Assumes the shape of the portion of the container that it occupies Can compress or expand to occupy a smaller or larger volume Molecules are held tightly together, usually in definite arrangement; wiggling only slightly Molecules are packed more closely together, but still move rapidly allowing them to slide over each other Molecules are far apart and are moving at high speeds, colliding repeatedly with each other

4.  Pure Substances and Mixtures Pure Substance (referred to as a substance)= matter that has a fixed composition and distinct properties  Classified as either.. – Elements (composed of only one kind of atom) – Compounds (composed of two ore more elements) Mixture = combinations of two or more substances in which each substance retains its own chemical identity and its own properties; compositions vary  Heterogeneous = do not have the same composition, properties, and appearance throughout the mixtures (Ex: sand, rocks, and wood)  Homogeneous = uniform throughout the mixtures (Ex: air, such as nitrogen, oxygen, etc)

5.  Separation of Mixtures Filtration (for heterogeneous mixtures)  Ex: to separate iron filings from gold ones, use a magnet to attract the iron Distillation (for homogeneous mixtures)  Ex: to separate salt from water, boil the solution; thus, water will evaporate while the salt is left behind because water has a much lower boiling point than table salt Chromatography  https://www.crimescene.com/store/bmz_cache/b/b3ac10ad9721f4d3399d6f4b82111806.image.220x223.jpg*

6. 1.3 – Properties of Matter  Physical properties = w/o changing identity and composition; (color, odor, density, melting point, boiling point, and hardness) Ex: When water evaporates, it changes from liquid to gas; however, its composition does not change; it is still water  Chemical properties = substance that may change or react to form other substances Ex: Flammability, which is the ability to burn a substance in the presence of oxygen, transforms one substance into a chemically different one  Intensive properties = does not depend on the amount of the sample being examined; (temperature, melting point, and density)  Extensive properties = depend on the quantity and amount of the sample; (measurements of mass and volume)

7. 1.4 – Units of Measurement  SI Units Physical Quantity Name of UnitAbbreviation MassKilogramkg LengthMeterm TimeSecondsasa Electric currentAmpereA TemperatureKelvinK Luminous intensityCandelacd Amount of substanceMolemol

8.  Derived SI Units Density = mass volume  Practice Problem!!: ** Calculate the density of mercury if 1.00 x 10 2 g occupies a volume of 7.36 cm 3. (Answer) Density = mass = 1.00 x 10 2 g = 13.6 g/cm 3 volume 7.36 cm 3

9. 1.5 – Uncertainty in Measurement  Precision and Accuracy Precision = a measure of how closely individual measurements agree with one another Accuracy = how closely individual measurements agree with the correct, or “true” value http://celebrating200years.noaa.gov/magazine/tct/accuracy_vs_precision_556.jpg*

10.  Significant Figures Guidelines to determine the number of sig. figures: Nonzero digits are always significant (214= THREE significant figures) Zeros between nonzero digits are always significant (1004 = FOUR significant figures) Zeros at the beginning of a number are never significant (0.01 = ONE significant figure) Zeros that fall both at the end of a number and after the decimal point are always significant (4.0 = TWO significant figures)

11.  Significant Figures in Calculations Multiplication and Division: the result must be reported with the same number of significant figures as the measurement with the fewest significant figures Addition and Subtraction: the result cannot have more digits to the right of the decimal point than any of the original numbers

12. 1.6 – Dimensional Analysis  Conversion factor given unit x desired unit = desired unit given unit  Example: *Converting 8.00 meters to inches 8.00 m x 100 cm x 1 in. = 315 inches 1 m 2.54 cm