2. Section 3.1 Chapter 3: Scientific Measurement

3. Scientific Notation or how to deal with large numbers...

4. Chemistry uses very large and very small numbers. Scientific Notation - coefficient x 10 - coefficient x 10 raised to a power - 10> coefficient > 1 - 4.32 x 10 2 coefficient exponent

5. exponent shows how many times the coefficient is multiplied by 10. 4.6 x 10 4 = 4.6 x 10 x 10 x 10 x 10 = 46,000

6. Scientific Notation to Regular Notation If the exponent is positive, move the decimal point to the right  5.3 x 10 6 = 5,300,000 If the exponent is negative, move the decimal point to the left  5.3 x 10 - 6 = 0.0000053

7. Regular Notation to Scientific Notation Use + if you moved the decimal to the left. Use – if you moved the decimal to the right 630,000,000 = 6.3 x 10 8 0.000000063 = 6.3 x 10 - 8

8. If coefficient smaller then exponent bigger; if coefficient bigger then exponent will get smaller. 54256 = 5.4256 x 10 4 0.00248 = 2.48 x 10 - 3 Remember! only 1 number in front of decimals

9. Let’s Practice... 7348000 = 7348000 = 7.348 x 10 6 0.24854 = 0.24854 = 2.4854 x 10 - 1 5842000 = 5842000 = 5.842 x 10 6 0.0000124 = 0.0000124 = 1.24 x 10 - 5 Do I move the decimal to the right or the left?

10. Sometimes you may need to convert between notations... If you make one side bigger, make the other side smaller Example: 6.3 x 10 4 = _______ x 10 2 6.3 x 10 2 = _______ x 10 4 6.3 x 10 -4 = _______ x 10 -2 6.3 x 10 -3 = _______ x 10 2 630.063.000063

12. Scientific Notation: Multiplication Scientific Notation: Multiplication  Multiply the coefficients  Add the exponents (3.0 x 10 4 ) x (2.0 x 10 2 ) = (3.0 x 2.0) x 10 4+2 = 6.0 x 10 6 make sure final coefficients – between 1 and 10!!!

13. Scientific Notation: Division Scientific Notation: Division  Divide the coefficients  Subtract the exponents 6.0 x 10 5 2.0 x 10 3 = (6.0 / 2.0) x 10 5-3 = 3.0 x 10 2 why? 10 x 10 x 10 x 10 x 10 10 x 10 x 10

14. Scientific Notation: Scientific Notation: Addition and Subtraction 1st make exponents the same, 1st make exponents the same, then align decimal points then align decimal points 5.40 x 10 3 5.40 x 10 3 + 6.00 x 10 2 + 6.00 x 10 2 ________________ ________________ 5.40 x 10 3 + 0.600 x 10 3__________________ 6.00 x 10 3 6.00 x 10 3

15. Significant Figures Measurements not more reliable than measuring tool Significant Figures = all digits known precisely in a measurement, + 1 estimated digit SIX RULES to determine if measured values are significant:

17. With the ruler, measure the width of your page of notes What is its’ width? How many digits are you sure of? How many do you interpolate or “guess”? How many significant digits in total?

18. T

19. Sig. Figs. in Calculations least answer rounded to the least number of decimal places in agreement 12.52 349.0 + 8.24 369.76 = 369.8 = Adding/Subtracting = 3.698 x 10 2

20. round number w/ the least sig. figs. 7.55 x 0.34 2.567 =2.6 2 sig. figs. Multiplying and Dividing

21. Examples 61.2 9.35 + 8.6 79.15 = 79.2 7.92 x 10 1 34.61 - 17.3 17.31 1.73 x 10 1 2.10 x.70 = 1.47 = 1.5

22. Percent Error Percent Error Used to evaluate accuracy of a measurement in lab. Two parts: 1.Actual Value –‘correct’ value 2. Experimental Value - measured in the lab

23. The Equation... % Error = Actual Amt - Experiment Amt x 100 Actual Amt. Will you have negative % errors?

24. Section 3.3 International System Of Units

25. Why is it important to have one standard for measurement? To ensure consistent & repeatable measurements

26. Why is the metric system preferred over the English system? All units multiplies of 10. Easy to convert

27. Which countries don’t use metrics in everyday life? Only 3 Liberia (West Africa) Myanmar (or Burma S.W. Asia) United States

28. 1st established in France 1790’s 1960, International System of Units(SI) SI - revised version of metric system Metric System

29. International System of Units  Seven SI Units: QuantityUnitSymbol lengthmeterm masskilogramkg timeseconds electric currentampereA thermodynamic temperaturekelvinK amount of substancemolemol luminous intensitycandelacd

30. Common SI-English Equivalent Quantities English Equivalent Mass Length 1 kilometer(km)1000(10 3 )m0.62miles(mi) 1 meter(m)100(10 2 )m1.094yards(yd) 1000(10 3 )mm39.37inches(in) 1 centimeter(cm)0.01(10 -2 )m0.3937in Volume 1 kilometer(km)1000(10 3 )m0.62mi 1,000,000(10 6 ) cubic centimeters 35.2cubic feet (ft 3 )1 cubic meter(m 3 ) 1 cubic decimeter (dm 3 ) 1000cm 3 0.2642 gallon (gal) 1.057 quarts (qt) 1 cubic centimeter (cm 3 ) 0.001 dm 3 0.0338 fluid ounce 1 kilogram (kg)1000 grams2,205 pounds (lb) 1 gram (g)1000 milligrams0.03527 ounce(oz) Table 1.4 QuantitySI UnitSI Equivalent English to SI Equivalent 1 mi = 1.61km 1 yd = 0.9144m 1 foot (ft) = 0.3048m 1 in = 2.54cm (exactly!) 1 ft 3 = 0.0283m 3 1 gal = 3.785 dm 3 1 qt = 0.9464 dm 3 1 qt = 946.4 cm 3 1 fluid ounce = 29.6 cm 3 1 (lb) = 0.4536 kg 1 lb = 453.6 g 1 ounce = 28.35 g

31. yottaY10 24 zettaZ10 21 exaE10 18 petaP10 15 teraT10 12 gigaG1 000 000 00010 9 megaM1 000 00010 6 kilok100010 3 hectoh10010 2 dekada1010 1 decid0.110 -1 centic0.0110 -2 millim0.00110 -3 microµ0.000 00110 -6 nanon0.000 000 00110 -9 picop10 -12 femtof10 -15 attoa10 -18 zeptoz10 -21 yoctoy10 -24 There are 20 SI Prefixes:

32. G 10 9 M 1 000 00010 6 k 1 00010 3 10010 2 deka1010 1 base … b110 0 decid0.110 -1 centic0.0110 -2 millim0.00110 -3 microµ0.000 00110 -6 nanon0.000 000 00110 -9 1 000 000 000 giga mega kilo hecto h da

34. “Give Me knowledge brother d.c. mun” Giga Mega kilo Base- g,m,L (great mr. Lincoln) deci centi milli u(= micro ) nano

35. 1000 cm = ______ mm 3789.23 mm = ______ dm 10.34 kg = ______ mg 10.34 g = ______ kg

36. 93 cm = ______ Mm 3789.23 mL = ______ nL 3.78923 Gm = ______ dm

37. Section 3.4 Density

38. Example: Calculate the density of mercury if 1.00 x 10 2 g occupies a volume of 7.36 cm 3. D = m v 13.586 = 1.00 x 10 2 g 7.36 cm 3 = 13.6 = 1.36 x 10 1 g/cm 3

39. 1 st Semester Lecture Ends Here

40. Example: A plastic ball has a density of.54 g/cm 3. Will the plastic ball sink or float in a container of gasoline,.66 g/cm 3. float

41. Specific Gravity Specific gravity = density of substance density of water density of water density of gold = 19.3 g/cm 3 = 19.3 density of water 1.000g/cm 3 density of water 1.000g/cm 3

42. Section 3.5 Temperature

43. A. Temperature scales Boiling pt. of water Freezing pt. of water Fahrenheit CelsiusKelvin 212 F 32 F 100 C 0 C 373 K 273 K Common Temperature scale in U.S. Lowest temp possible all particles motion stops is O K or absolute zero.

44. http://www.212movie.com/

45. Equations for Temperature Conversions K = o C + 273 Memorize these equations!

46. Normal body temp is 98.6 F. Convert to Celsius & Kelvin. C = 37 K = C + 273 K = 37 + 273 K = 310 No degree sign! o

47. boiling point of water on Everest is 343 K, what is this in Celsius? K = C + 273 343 = C + 273 343 - 273= C C = 70 o

48. Dimensional Analysis – Get p. 16-17 ready uses units to solve problems & check answers. 1. Use equivalence statement to get conversion factor. 2. Pick conversion factor that cancels appropriate unit. 3. Multiply quantity by conversion factor. 4. Check Sig Figs. 5. Ask whether your answer makes sense.

49. Sample Problem 1.2 Converting Units of Length PROBLEM: What is the price of a piece of copper wire 325 centimeters (cm) long that sells for $0.15/ft?

50. 2.54 cm = 1 in = 325 cm x in 2.54 cm = 128 in

51. Use the Unit cancelation Method. Use the Unit cancelation Method. It’s easier = 325 cm x 1 ft 12 inch 1 inch 2.54 cm $ 0.15 ft

52. Dimensional Analysis Review 1 week John finds 27 boggles on the ground. Realizing that in Slopoland they are being devalued and Discontinued, he traded them in until he gets all of his currency in slopos. Fred is willing to exchange 14 boggles for each Jangle John is willing to exchange 7 Dopies for each Jangle. And the bank will accept 1/6 of a Dopey for each Slopo If John can find 27 boggles per week, how many slopos can he earn in 1 Year. can he earn in 1 Year.

53. Review A student is given 3.5 grams of Chocolate for every 2 miles of running.Each run is 4.0 miles. How many pounds would they receive after running for 2.0 months. Students run twice per day (1 kg = 2.2 pounds) A student is given 3.5 grams of Chocolate for every 2 miles of running.Each run is 4.0 miles. How many pounds would they receive after running for 2.0 months. Students run twice per day (1 kg = 2.2 pounds)

54. Review A student is given 4.0 grams of Chocolate for every 3 miles of running. Each run is 2.0 miles. How many pounds would they receive after running for 3.0 months. Students run twice per day (1 kg = 2.2 pounds) A student is given 4.0 grams of Chocolate for every 3 miles of running. Each run is 2.0 miles. How many pounds would they receive after running for 3.0 months. Students run twice per day (1 kg = 2.2 pounds)

55. Chp 3 QUIZ 1. How many sig figs are in: 7300 2. How many sig figs are in: 7300.0 4. Which above is best? Why? 6. 73 + 27 = _______ _________ __________ Number FROM 1-10. Skip lines & show work, sig figs, sci. not. 5. G M K b (gml) d c mun. Copy & finish the roots and write the exponents – Giga 10 9 7. 10.0 x 30.00 = _________ _________ _______? 8. 1 dm 3 = 1 __ = 1000 ___ = 1000 ___ = 1000 ___ 9. 3700.42 mg = ______ g 10. A dice with 2.0 cm sides is 4.00 g. What’s its’ density? (show all steps). Will it float? 3. What’s the difference between accuracy/precision?

56. Chp 3 QUIZ 1. How many sig figs are in: 2 2. How many sig figs are in: 5 4. Which above is best? Why? 6. 73 + 27 = 110 1.10 x 10 2 Number FROM 1-10. Skip lines & show work, sig figs, sci. not. 5.G M K b (gml) d c mun. Copy & finish the roots write the exponents – Giga Mega Kilo base deci centi milli micro nano 10 9 6 3 0 -1 -2 -3 -6 -9 7. 10.0 x 30.00 = 3.00 x 10 2 8. 1 dm 3 = 1 L = 1000 cm 3 = 1000 mL = 1000 c.c.’s 9. 3700.42 mg 10. A dice with 2.0 cm sides is 4.00 g. What’s its’ density? (show all steps). Will it float? 3. What’s the difference between accuracy/precision? 1 g = 3.70042 g 1000mg

57. Chp 3 QUIZ 1. How many sig figs are in: 2 2. How many sig figs are in: 5 4. Which above is best? Why? 6. 73 + 27 = 100 1.00 x 10 2 Number FROM 1-10. Skip lines & show work, sig figs, sci. not. 5.G M K b (gml) d c mun. Copy & finish the roots write the exponents – Giga Mega Kilo base deci centi milli micro nano 10 9 6 3 0 -1 -2 -3 -6 -9 7. 10.0 x 30.00 = 3.00 x 10 2 8. 1 dm 3 = 1 L = 1000 cm 3 = 1000 mL = 1000 c.c.’s 9. 3700.42 mg 10. A dice with 2.0 cm sides is 4.00 g. What’s its’ density? (show all steps). Will it float? 3. What’s the difference between accuracy/precision? 1 g = 3.70042 g 1000mg

58. Name Job +2 Yes/No Why 3 reasons Intro sentence Reason Why Example +2 Intro sentence Reason Why Example +2 Yes/No +2 Why 3 reasons Declare better off Intro sentence Reason Why Example +2 TAKE NOTES

59. Let’s review...

60. Scientific Measurements Scientific Measurements A measurement assigns a numerical value for a physical property. Two parts: A Number and a Unit A Number and a Unit Without a unit the # is not valid Without a unit the # is not valid I have 3 3 grams? No, 3 pigs

61. Types of Measurement   Quantitative Measurement -   numerical  basketball - diameter = 31 cm.   Qualitative Measurement –   descriptions, non-numerical  The basketball is brown.

62. Qualitative or Quantitative? The solution was copper colored. The solution weighed 150g. The compound was very dense. The compound had a density of 1.54g/l Which type of measurement do scientists prefer? Why?

63. Section 3.2 Uncertainty in Measurements

64. Two types of Quantitative Measurements Two types of Quantitative Measurements A. Accuracy How close a single measurement comes to the actual value

65. How close several measurements measurements measurements are to each other – how repeatable repeatable repeatable B. Precision

66. A CB Compare the accuracy and precision of the following:

67. Rule 1 non-zero All non-zero numbers are significant (counting numbers 1-9) 123 4.7.7432 How many Significant Figures?

68. Rule 2 “trapped” All “trapped” zeros are significant (between #’s 1-9) 7003 40.79 1.5003 How many Significant Figures? 0 0 0 0 0 Trapped Zeros

69. Rule 3 “Leading” “Leading” zeros NEVER significant 0.00701 0.4102 0.000099 How many Significant Figures? 00 The Zeros are leading!

70. Rule 4 After a decimal point all zeroes, other than leading, are significant. 0.0070100 0.41020 0.0000990

71. Rule 5 “placeholders” Zeros “placeholders” at end of a # is NOT significant. 300 7000 27210 How many Significant Figures? A zero holding a place 0

72. Rule 6 Unlimited Unlimited number of sig. figs. Defined quantities 60 minutes = 1 hour 100 cm = 1 m Involves counted objects There are 36 students in the class. 6.5 counselors “that can’t be”

73. How many sig. figs. are in the following measurements? 80.41 g 71,000,000 m 0.00023 L 10 basketballs 93.00 inches 3600 sec = 1 hour

74. Round the following numbers to 3 significant figures: 1.035 g = 0.00000789 m = 578,000 mL = 1.04 g 7.89 x 10 -6 m 5.78 x 10 5 mL 0.06055 x 10 -2 = 6.06 x 10 -4 g

78. 1 dm 1 cm 1 mm 1 dm 1 dm 2 1 dm 1 dm 3 1 cm 1 cm 2 1ml 1 cm 1 cm 3 1 dm 3 = 10cmx10cmx10cm = 1000 cm 3 = 1000 ml = 1 liter =