1 Ch. 1a - The Nature of ScienceDefining Science Problem-Solving Scientific Method Experimental Design

2 A. Defining Science Pure Scienceresearch that adds to the body of scientific knowledge has no practical use Applied Science (Technology) the practical application of scientific knowledge

3 A. Defining Science PURE APPLIED human genetics polymer scienceatomic theory study of the human ear APPLIED DNA fingerprinting Lycra® spandex nuclear weapons hearing aids

4 A. Defining Science Life Science the study of living organismsEarth Science the study of Earth and space Physical Science the study of matter and energy chemistry & physics

5 B. Problem-Solving 1. Identify the problem. What do you know?What do you need to know? 2. Plan a strategy. Look for patterns. Break the problem into smaller steps. Develop a model.

6 Identify - Plan - Execute - EvaluateB. Problem-Solving 3. Execute your plan. 4. Evaluate your results. Did you solve the problem? Is your answer reasonable? Identify - Plan - Execute - Evaluate

7 C. Scientific Method Hypothesis - testable predictionTheory - explanation of “why” based on many observations & experimental results Scientific Law - prediction of “what” describes a pattern in nature

8 THEY ARE NOT SET IN STONE!C. Scientific Method Theories and laws are well-accepted by scientists, but... THEY ARE NOT SET IN STONE! They are revised when new information is discovered.

9 C. Scientific Method 1. Determine the problem. 2. Make a hypothesis.3. Test your hypothesis. 4. Analyze the results. 5. Draw conclusions.

10 C. Scientific Method 1. Determine the problem.When the Titanic sank, what happened to the water level on shore? 2. Make a hypothesis. The water level rose. The water level dropped. The water level stayed the same.

11 C. Scientific Method 3. Test your hypothesis. 4. Analyze the results.How could we test our hypothesis? 4. Analyze the results. What happened during our test? 5. Draw conclusions. Was our hypothesis correct? Is further testing necessary?

12 D. Experimental Design Experiment - organized procedure for testing a hypothesis Key Components: Control - standard for comparison Single variable - keep other factors constant Repeated trials - for reliability

13 D. Experimental Design Types of Variables Independent Variableadjusted by the experimenter what you vary Dependent Variable changes in response to the indep. variable what you measure

14 D. Experimental Design Hypothesis:Storing popcorn in the freezer makes it pop better. Control: Popcorn stored at room temp.

15 D. Experimental Design Single variable: Storage temperature Constants:Popcorn brand Freshness Storage time Popper

16 D. Experimental Design Independent Variable: Storage temperatureNumber of unpopped kernels

17 Ch. 1.2a - Measurement I. Units of Measurement Number vs. QuantitySI Base Units & Prefixes Derived Units Density Calculations

18 A. Number vs. Quantity Quantity - number + unit UNITS MATTER!!

19 B. SI Units Quantity Base Unit Symbol Length meter m Mass kilogram kgTime second s Temp kelvin K Current ampere A

20 D M V D = M V C. Derived Units Combination of base units.Volume - length  length  length 1 cm3 = 1 mL dm3 = 1 L Density - mass per unit volume (g/cm3) D M V D = M V

21 D M V D. Density V = 825 cm3 M = DV D = 13.6 g/cm3An object has a volume of 825 cm3 and a density of 13.6 g/cm3. Find its mass. GIVEN: V = 825 cm3 D = 13.6 g/cm3 M = ? WORK: M = DV M = (13.6 g/cm3)(825cm3) M = 11,220 g D M V

22 D M V D. Density D = 0.87 g/mL V = M V = ? M = 25 g V = 25 g 0.87 g/mL1) A liquid has a density of 0.87 g/mL. What volume is occupied by 25 g of the liquid? GIVEN: D = 0.87 g/mL V = ? M = 25 g WORK: V = M D D M V V = g 0.87 g/mL V = 28.7 mL

23 D M V D. Density M = 620 g D = M V = 753 cm3 D = ? D = 620 g 753 cm32) You have a sample with a mass of 620 g & a volume of 753 cm3. Find density. GIVEN: M = 620 g V = 753 cm3 D = ? WORK: D = M V D M V D = g 753 cm3 D = 0.82 g/cm3

24 III. Unit Conversions SI Prefix Conversions Dimensional AnalysisCh. 1.2b - Measurement III. Unit Conversions SI Prefix Conversions Dimensional Analysis

25 A. SI Prefix Conversions1. Find the difference between the exponents of the two prefixes. 2. Move the decimal that many places. To the left or right?

26 A. SI Prefix Conversions= 532 m = _______ km 0.532 NUMBER UNIT NUMBER UNIT

27 A. SI Prefix ConversionsSymbol Factor mega- M 106 kilo- k 103 deci- d 10-1 centi- c 10-2 move left move right milli- m 10-3 micro-  10-6 nano- n 10-9 pico- p 10-12

28 A. SI Prefix Conversions0.2 1) 20 cm = ______________ m 2) A = ______________ mA 3) 45 m = ______________ nm 4) 805 dm = ______________ km 32 45,000 0.0805

29 B. Dimensional AnalysisThe “Factor-Label” Method Units, or “labels” are canceled, or “factored” out

30 B. Dimensional AnalysisSteps: 1. Identify starting & ending units. 2. Line up conversion factors so units cancel. 3. Multiply all top numbers & divide by each bottom number. 4. Check units & answer.

31 B. Dimensional AnalysisLining up conversion factors: = 1 1 in = 2.54 cm 2.54 cm cm 1 = 1 in = 2.54 cm 1 in in

32 B. Dimensional AnalysisYour European hairdresser wants to cut your hair 8 cm shorter. How many inches will he be cutting off? cm in 8 cm 1 in 2.54 cm = 3.15 in 

33 B. Dimensional AnalysisHow many milliliters are in 1 quart of milk? qt mL 1 qt 1 L 1.057 qt 1000 mL 1 L = 946 mL

34 B. Dimensional Analysis5) Assume your mass is 55 kg. How many pounds do you weigh? kg lb 55 kg 2.2 lb 1 kg = 121 lb

35 B. Dimensional Analysis6) How many feet long is a 5K (5 km) race? km ft 5 km 1 mi 1.609 km 5280 ft 1 mi = 16,408 ft

36 B. Dimensional Analysis7) How many grams does a 10-lb. bag of potatoes weigh? lb g 10 lb 1 kg 2.2. lb 1000 g 1 kg = 4545 g

37 B. Dimensional Analysis8) Taft football needs 550 cm for a 1st down. How many yards is this? cm yd 550 cm 1 in 2.54 cm 1 ft 12 in 1 yd 3 ft = 6.01 yd

38 II. Graphing Types of graphs Graphing & DensityCh Measurement II. Graphing Types of graphs Graphing & Density

39 A. Types of Graphs Line Graphshows the relationship between 2 variables Dependent Variable Independent Variable

40 A. Types of Graphs Bar Graph shows information collected by counting

41 A. Types of Graphs Pie Graphshows distribution of parts within a whole quantity

42 B. Graphing & Density Mass (g) Volume (cm3)

43 Hazard Coding System MSDS Safety RulesLABORATORY SAFETY Hazard Coding System MSDS Safety Rules

44 HAZARD CODING SYSTEM FLAMMABILITY HEALTH REACTIVITY (STABILITY)SPECIAL

45 4 2 3 4 HAZARD CODING SYSTEM 4 Will burn readily Will not burn LeastLeast Serious 4 Most 4 2 3 4 Will burn readily Will not burn

46 MSDS Material Safety Data Sheet On file for all purchased chemicals.Includes all information shown on a chemical label and more. Different formats are used by different chemical companies.