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

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

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

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

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.

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

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

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.

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

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.

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?

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

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

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

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

D. Experimental Design Independent Variable: Storage temperature Number of unpopped kernels

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

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

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

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

D M V D. Density V = 825 cm3 M = DV D = 13.6 g/cm3 An 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

D M V D. Density D = 0.87 g/mL V = M V = ? M = 25 g V = 25 g 0.87 g/mL 1) 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 = 25 g 0.87 g/mL V = 28.7 mL

D M V D. Density M = 620 g D = M V = 753 cm3 D = ? D = 620 g 753 cm3 2) 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 = 620 g 753 cm3 D = 0.82 g/cm3

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

A. SI Prefix Conversions 1. Find the difference between the exponents of the two prefixes. 2. Move the decimal that many places. To the left or right?

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

A. SI Prefix Conversions Symbol 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

A. SI Prefix Conversions 0.2 1) 20 cm = ______________ m 2) 0.032 A = ______________ mA 3) 45 m = ______________ nm 4) 805 dm = ______________ km 32 45,000 0.0805

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

B. Dimensional Analysis Steps: 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.

B. Dimensional Analysis Lining up conversion factors: = 1 1 in = 2.54 cm 2.54 cm 2.54 cm 1 = 1 in = 2.54 cm 1 in 1 in

B. Dimensional Analysis Your 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 

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

B. Dimensional Analysis 5) Assume your mass is 55 kg. How many pounds do you weigh? kg lb 55 kg 2.2 lb 1 kg = 121 lb

B. Dimensional Analysis 6) 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

B. Dimensional Analysis 7) 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

B. Dimensional Analysis 8) 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

II. Graphing Types of graphs Graphing & Density Ch. 1.3 - Measurement II. Graphing Types of graphs Graphing & Density

A. Types of Graphs Line Graph shows the relationship between 2 variables Dependent Variable Independent Variable

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

A. Types of Graphs Pie Graph shows distribution of parts within a whole quantity

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

Hazard Coding System MSDS Safety Rules LABORATORY SAFETY Hazard Coding System MSDS Safety Rules

HAZARD CODING SYSTEM FLAMMABILITY HEALTH REACTIVITY (STABILITY) SPECIAL

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

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.