Measurement and Problem Solving 1) Circle the letter of each sentence that is true about numbers expressed in scientific notation. a. A number expressed in scientific notation is written as the product of a coefficient and a power of 10. b. The power of 10 is called the exponent c. The coefficient is always a number greater than or equal to one and less than ten. d. For numbers less than one, the exponent is positive 2) Circle the letter of each sentence that is true about significant figures. a. All nonzero digits in a measurement are assumed to be significant b. Zeros appearing between nonzero digits are never significant c. Final zeros to the right of the decimal point are always significant d. Zeros acting as placeholders in front of nonzero digits to the right of the decimal are not significant. e. Zeros to the left of the decimal point that act as placeholders are not significant. 3) Use the following equation to answer a- 4) Use the following equation below to d. answer a-d: 0.00076 = 7.6 x 10? 76 000 000 =7.6 x 10? a. How many places did the decimal a. What direction did the decimal point point move? 4 In which direction? right move? left b. To make the equation true, does 7.6 b. To make a true equation, does 7.6 need to be multiplied by a number need to be multiplied by a number greater than one?no, less than 1 greater than one or less than one? c. Is the exponent for 10 positive or greater negative? negative c. Is the exponent for 10 positive or d. What exponent makes the equation negative? positive true? -4 d. What exponent makes the equation true? +7 5) What is the meaning of “accepted 6) The accepted value of a length value” with respect to an experimental measurement is 200cm, and the measurement? Value that can be looked experimental value is 198cm. Circle up or verified; i.e. the “right” answer the letter of the value that shows the percent error of this measurement. a. 2% b. –2% c. 1% d. –1% 7) In the measurement 43.52 cm, which 8) How many significant figures are in the digit is the most uncertain? measurement 6.80 m? a. 4 b. 3 c. 5 d. 2 a. 2 b. 3 c. 4 d. 5 Measurement and Problem Solving 9) Circle the letter of the answer in which 503,000,000 is written correctly in scientific notation a. 5.03 x 10-8 b. 503 x 106 c. 5.03 x 108 d. 503 million 10) Round the following as indicated. a. 65.145 m to 4 significant digits 65.15 b. 100.1 C to 1 significant digit 100 C c. 155 cm to 2 significant digits 160 d. 0.000718 to 2 significant digits 0.00072 e. 65.145 m to 3 significant digits 65.1 11) Is the following sentence true or false? An answer is as precise as the most precise measurement from which it was calculated False, it is as precise as the least precise from which it was calculated 12) All metric units are based on multiples of what number? 10 13) What is a derived unit? Unit that requires two directly measured units to be manipulated Give an example mph 14) List SI Base unit, the Symbol and the Commonly used Lab unit for the following measurements: Length meter Mass kg Temperature K Time s Volume L (liquid) cm3 (solid) Density g/ml or g/cm3 Using Significant Figures Identify the number of significant digits in the following quantities. 1. 3.58 g 3 2. 804.58 kg 5 3. 14.809 cm 4 4. 0.007832 cg 4 5. 107.334 km 6 6. 130 004.5 mm 7 7. 0.0004898 mm 4 8. 250.0 km 4 9. 3000 cm 1 10. 14.380 s 5 11. 307 cm 3 12. 0.00450 cm 3 Measurement and Problem Solving Solve each of the following and express the answer in the correct number of significant digits (when appropriate, use scientific notation) 13. 4.52 g + 13.8 g + 7.9483 g 14. (48.4398 m)(1.52 m) 73.6 m2 26.3g 15. 82.5 cm + 13.56 cm 96.1 cm 16. 13.80 cm – 6.0741 cm 7.73 cm 17. 16.8892 km + 3.5 km 20.4 km 18. 8.472 cg – 1.440 cg 7.032 cg 19. 45.456 g + 3.56 g 49.02 g 20. 30 s – 1.442 s 28 s 21. 106.22 mm + 80.0 mm 186.2 mm 23. 30.44 kg + 3.9422 kg 34.38 kg 22. 54.00 g – 30.220 g 23.78 g 25. (8.4 cm)(3.58 cm) 3.0 x 101 26. 35.068 km3 ÷ 5.7 km 5.2 km2 28. 85.0869 m2 ÷ 9.0049 m 9.4490m 27. (1.075m)(2.0m) 2.2 m2 24. 1.45050 kg – 0.00667 kg 1.44383 kg 29. (3.0899 mm)(22.4 mm) 69.2 mm2 30. 0.00826 cm2 ÷ 0.00033 cm 25cm 31. (0.00457 cm)(0.18 cm) 8.2 x 10-4 cm2 32. 0.005600 mm2 ÷ 0.200 m 0.0280 m 33. (10.00 m)(84.767 m) 847.7 m2 34. 3.4500 cm2 ÷ 460 cm 0.0075cm Scientific Calculations Express the following in Scientific Notation 1. 700 7.0 x 102 6. 27 906 2.7906 x 104 2. 3 958 3.958 x 103 7. 1.56 1.56 x 100 6 3. 2 245 000 2.245 x 10 8. 0.0235 2.35 x 10-2 4. 98 000 000 000 9.8 x 1010 9. 0.000 79 7.9 x 10-4 -2 5. 0.097 9.7 x 10 10. 1 900 1.9 x 103 Express the following in Standard Form 11. 2.7 x 102 12. 5.9 x 10-3 15. 1.00 x 10-4 0.000100 16. 6.998714 x 0.0000006998714 10-7 13. 9.78 x 100 9.78 17. 1.9 z 101 19 14. 4.771 x 105 477100 18. 2.7 x 10-6 0.0000027 Calculate the following and express in the correct number of significant digits 19. 2.9 x 103 .097 20. (5.5 x102)(1.58x105)(0.0209) 1.7 x 106 3 x 104 21. 189 x 901 2,36 x 22. (7.654 x 10-10)(21)(987) 8,9 x 10-31 7.21 x 10-4 108 (29.5)(6.02 x 1023) 270 0.0059 Measurement and Problem Solving 23. (28.0)(0.082) 770 24. (976.5)(5.98)(123.45) 5.8 x 106 0.003 (0.047) (2.66) 25. 2.3 x 26. 4.2 x 109 4.3 x 107 5 11 19 (7.2x10 )(8.92x10 ) 10 98 (4.33 x10-2)(6.0 x10-1) 27. (0.002)(1.90)(24) 9.2 x 10- 28. 23 x 19 440 5 (987.20) 29. 159 x 1.9 3.0 x 102 30. (1.4 x 104)(2 x 10-6) 0.03 0.7 0.062 31. 6.54 9 32. .00278 .045 33. 39.8 – 1.297 38.5 34. 89 x 0.020 1.8 35. 2.3 + 129 + 57 188 2.6 x 103 36. 238 .091 Determine the number of significant digits 37. 6.021 g 4 38. 40.07 cm 4 39. 49.0 in 3 40. 0.024 in 2 41. 120 m 2 42. 0.0027 g 2 43. 20.00 g 4 44. 8000 in 1 45. 3.900 m 4 46. 7500.0 cg 5 47. .070 km 2 48. 139 cm 3 3 -4 49. 1.68 x 10 3 50. 2.0 x 10 2 51. 2000 L 1 52. 0.01001 m 4 Round each of the following to 3 significant digits 53. 8.838 54. 1997 2.00 x 55. 0.02345 56. 1000 1.00 x 103 103 .0235 23 57. 6.024 x 10 58. 1995.6 2. X 59. 29.4949 60. .00479 .00479 6.02 x 1023 103 29.5 61. 25.051 25.1 62. 973.44 973 63. 1.3449 64. 1.204 x 102 1,20 x 1.34 102