1. I II III I. Using Measurements MEASUREMENT

2. A. Accuracy vs. Precision  Accuracy - how close a measurement is to the accepted value  Precision - how close a series of measurements are to each other ACCURATE = CORRECT PRECISE = CONSISTENT

3. B. Percent Error  Indicates accuracy of a measurement your value accepted value

4. B. Percent Error  A student determines the density of a substance to be 1.40 g/mL. Find the % error if the accepted value of the density is 1.36 g/mL. % error = 2.9 %

5. C. Significant Figures  Indicate precision of a measurement.  Recording Sig Figs  Sig figs in a measurement include the known digits plus a final estimated digit 2.35 cm

6. C. Significant Figures  Counting Sig Figs  Count all numbers EXCEPT:  Leading zeros -- 0.0025  Trailing zeros without a decimal point -- 2,500  Captive zeros– 20004  Always count

7. 4. 0.080 3. 5,280 2. 402 1. 23.50 C. Significant Figures Counting Sig Fig Examples 1. 23.50 2. 402 3. 5,280 4. 0.080 4 sig figs 3 sig figs 2 sig figs

8. C. Significant Figures  Calculating with Sig Figs  Multiply/Divide - The # with the fewest sig figs determines the # of sig figs in the answer. (13.91g/cm 3 )(23.3cm 3 ) = 324.103g 324 g 4 SF3 SF

9. C. Significant Figures  Calculating with Sig Figs (con’t)  Add/Subtract - The # with the lowest decimal value determines the place of the last sig fig in the answer. 3.75 mL + 4.1 mL 7.85 mL 224 g + 130 g 354 g  7.9 mL  350 g 3.75 mL + 4.1 mL 7.85 mL 224 g + 130 g 354 g

10. C. Significant Figures  Calculating with Sig Figs (con’t)  Exact Numbers do not limit the # of sig figs in the answer.  Counting numbers: 12 students  Exact conversions: 1 m = 100 cm  “1” in any conversion: 1 in = 2.54 cm

11. C. Significant Figures 5. (15.30 g) ÷ (6.4 mL) Practice Problems = 2.390625 g/mL  18.1 g 6. 18.9g - 0.84 g 18.06 g 4 SF2 SF  2.4 g/mL 2 SF

12. D. Scientific Notation  Converting into Sci. Notation:  Move decimal until there’s 1 digit to its left. Places moved = exponent.  Large # (>1)  positive exponent Small # (<1)  negative exponent  Only include sig figs. 65,000 kg  6.5 × 10 4 kg

13. D. Scientific Notation 7. 2,400,000  g 8. 0.00256 kg 9.7  10 -5 km 10.6.2  10 4 mm Practice Problems 2.4  10 6  g 2.56  10 -3 kg 0.00007 km 62,000 mm

14. D. Scientific Notation  Calculating with Sci. Notation (5.44 × 10 7 g) ÷ (8.1 × 10 4 mol) = 5.44 EXP EE ÷ ÷ EXP EE ENTER EXE 78.1 4 = 671.6049383= 670 g/mol= 6.7 × 10 2 g/mol Type on your calculator:

15. I II III II. Units of Measurement MEASUREMENT

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

17. B. SI Units QuantityBase UnitAbbrev. Length Mass Volume Temp meter gram liter Kelvin m g l K Amountmolemol Symbol l m v T n

18. B. SI Units PrefixSymbolFactor GigaG10 9 MegaM10 6 Kilok10 3 BASE UNIT--10 0 Decid10 -1 Centic10 -2 Millim10 -3 Micro  10 -6 Nanon10 -9 Picop10 -12

19. C. Density  An object has a volume of 825 cm 3 and a density of 13.6 g/cm 3. Find its mass. GIVEN: V = 825 cm 3 D = 13.6 g/cm 3 M = ? WORK : M = DV M = (13.6 g/cm 3 )(825cm 3 ) M = 11,200 g

20. C. Density  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 V = 25 g 0.87 g/mL V = 29 mL

21. C. Density Mass (g) Volume (cm 3 )

22. I II III III. Unit Conversions MEASUREMENT

23. 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?

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

25. A. SI Units Prefixes PrefixSymbolFactor GigaG10 9 MegaM10 6 Kilok10 3 BASE UNIT--10 0 Decid10 -1 Centic10 -2 Millim10 -3 Micro  10 -6 Nanon10 -9 Picop10 -12 move left move right

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

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

28. 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.

29. B. Converting SI Units with Dimensional Analysis  Convert 10 liters to centiliters.  Identify starting and ending points  Starting point 10 liters, ending point centiliters  Draw a T chart, you can add boxes as you go  Line up conversion factors  Then cancel the unit top and bottom  Multiply across, divide top by the bottom. 10 liters 1 liter 100 cl End Point = 1000 cl or 1 X 10 3 cl

30.  How many milligrams are in 50 kilograms?  Identify starting and ending points  Start at 50 kg; end at mg  Draw a T chart, you can add boxes as you go  Line up conversion factors  Then cancel the unit top and bottom  Multiply across, divide top by the bottom 50 kg 1 kg 1000 g 1 g 1000 mg End Point = 50,000,000 mg or 5 X 10 7 mg B. Converting SI Units with Dimensional Analysis

31. I II III End Unit 1 STOP