1 Matter and MeasurementChapter #1

2 What is Chemistry? The study of the properties of substances and the changes they undergo.

3 Matter Anything that has mass and takes up space.Three states of matter: solid, liquid and gas.

4

5 Types of Matter Pure Substance: composition does not vary from sample to sample. Elements: made of only one type of atom (listed on P.T.) Iron (Fe) Compounds: made of more than one type of atom. Water (H2O) Mixtures: one or more substance physically combined. Homogenous (Solution): uniform throughout Sugar Water Heterogeneous: not uniform throughout. Granola

6 Properties of Matter Physical Properties Chemical PropertiesProperty that can be observed by the five senses without a chemical reaction. Intensive: do not depend on the amount of matter present Examples: color, melting point, density Extensive: do depend on the amount of matter present (measurements) Examples: mass, length, volume Chemical Properties Property that shows how a substance reacts. Examples: flammability

7 Physical and Chemical ChangesPhysical Change A change that occurs that does not change the composition of the substance. Examples: cutting, phase changes Chemical Change A change that occurs that creates a new substance with new properties. Examples: burning, baking,

8 Give it some thought…. Which of the following is a physical change and which is a chemical change? Plants use carbon dioxide and water to make sugar Water vapor in the air on a cold day forms frost.

9 What are some ways that you can separate a mixture?Filtration Physically separating it. Distillation And many other ways!

10 Accuracy versus PrecisionAccuracy refers to the proximity of a measurement to the true value of a quantity. Precision refers to the proximity of several measurements to each other. © 2009, Prentice-Hall, Inc.

11 Percent Error

12 Measuring with Significant DigitsWhat is the measurement of the line of each of the rulers?

13 Significant Figures The term significant figures refers to digits that were measured. When rounding calculated numbers, we pay attention to significant figures so we do not overstate the accuracy of our answers. Use the Atlantic/Pacific Rule:

14 Determine the Number of Significant Figures:cm 1100 km L 100. mg

15 Calculations with Significant FiguresWhen addition or subtraction is performed, answers are rounded to the least significant decimal place. When multiplication or division is performed, answers are rounded to the number of digits that corresponds to the least number of significant figures in any of the numbers used in the calculation. © 2009, Prentice-Hall, Inc.

16 Practice on Addition and SubtractionEx) g g g = ____________________________ Reported Answer = _______________________ 1) cm cm = ________________________________ 2) kg – kg = __________________________________ 3) g – g = __________________________________ 4) mL – mL = ___________________________________

17 Practice on Multiplication and DivisionEx) (6.221 cm)(5.2 cm) = ____________________________ Reported Answer = ____________________________ 1) g / 6.33 mL = _____________________________ 2) (16.00 cm)(2.5 cm)(3.66 cm) = ___________________________ 3) (3.24 m)(7.00 m) = ____________________________ 4) 710 m / 3.0 s = _____________________________

18 Types of Measurement Qualitative QuantitativeObservation that do not include measurements Ex) color, odor, texture, state of matter Quantitative Data that can be measured Ex) mass, volume, density, length, time

19 Units of Measurement SI Units (Systeme International d’Unites) Physical Quantity Name of Unit Abbreviation * Mass Kilogram kg Length Meter m Time Second sec (s) Temperature Kelvin K Amount of Substance Mole mol Electric Current ampere A Luminous Intensity candela cd

20 Some Common Measurements

21 Temperature A measure of the average kinetic energy of particles in a sample  Temperature Conversions- K = °C °C = (°F - 32) / 1.8 °F = (1.8)(°C ) + 32

22 Volume Other units: mL, L Important Conversions to remember:Cube: length x width x height (length)3 Other units: mL, L Important Conversions to remember: 1 mL = 1 cm3 1 L = 1 dm3

23 Beginning Metric Conversions1 cm = 10-2 m (100 cm = 1 m) 1 mm = 10-3 m (1000 mm = 1 m) 15 m = ________ cm 15 m3 = ________cm3

24 Density Density = Mass/VolumeAll substances have a values for density at a given temperature and pressure. The density of water is 1.00 g/mL Derived Units: Units that are combined Examples: g/mL, cm3

25 Challenge! Find the thickness of a piece of aluminum foil to the correct number of significant digits in cm. Some important information: The Density of Aluminum is 2.70 g/cm3. You will turn in: Data Table Calculations (Remember Sig. Figs.!) The thickness of the foil is __________________ cm.

26 Metric Conversions

27