1. Warm up:
What is the scientific method?
What is it used for?

2. The Scientific Method

3. The Scientific Method
general approach to solving problems

4. The Scientific Method
Step 1: State the problem.
-Typically stated as a question

5. Step 2: Research the Problem
The Scientific Method
Step 2: Research the Problem
Gather info, read journals, communicate with others

6. The Scientific Method Step 3: Hypothesizing
proposing an explanation, theorizing, predicting, testable statement (if –then)

7. Step 4: Testing your hypothesis
The Scientific Method
Step 4: Testing your hypothesis
experimenting

8. The Scientific Method Independent Variable
The variable you change on purpose in the experiment

9. The Scientific Method Dependent Variable
The response to the independent variable

10. The Scientific Method Control
The group or experimental subject that does not receive the independent variable

11. The Scientific Method Constants
Conditions that remain the same in the experiment

12. Step 5: Recording and analyzing the data
The Scientific Method
Step 5: Recording and analyzing the data
Data tables and graphs of results

13. Step 6: Stating the conclusion
The Scientific Method
Step 6: Stating the conclusion
What does the data/results mean, is the hypothesis correct?

14. The Scientific Method Step 7: Retesting
Results are validated when experiments are repeated with the same results

15. The Scientific Method
hypothesis is a testable statement that serves as a basis for making predictions and for carrying out further experiments

16. The Scientific Method
model is usually proposed after a hypothesis is shown to be correct. A model that successfully explains many phenomena may eventually become part of a theory

17. The Scientific Method
theory is a broad generalization that explains a body of facts or phenomena, and it is an extensively tested explanation for experimental results and explains why

18. The Scientific Method
scientific law is a concise statement that summarizes the results of a broad variety of observations and experiments but does not try to explain it.

19. The Metric System and Measurement

20. Qualitative vs. Quantitative
The following observations are qualitative.
The building is really tall.
It takes a long time for me to ride my bike to the store.
I live really far away.
The following observations are quantitative.
The river is 31.5 m deep.
The cheese costs $4.25 per pound.
It is 75o F outside today.
Critical Thinking Questions
What is the difference between qualitative and quantitative observations?

21. SI System and Base Units
The basic unit of length is the _____ and is measured by a _____

22. SI System and Base Units
The basic unit of mass is a _____ and can be measured by a ______

23. SI System and Base Units
The basic unit of time is _____ and it can be measured by a _____

24. SI System and Base Units
The basic unit of Temperature is _____ and can be measured by a _____

25. SI System and Base Units

26. SI System and Base Units
The basic unit for the amount of a substance is a mole

27. SI System and Base Units
The basic unit for volume is the _____ and it can be measured with a ____ or a _____

28. SI System and Base Units

29. SI System and Base Units
Density = _____/_____
The basic unit for density is _____, _____, or _____

30. SI System and Base Units

31. SI System and Base Units
The basic unit for energy is a _____

32. Base Units and Prefix Handout
SI System
Base Units and Prefix Handout

33. Accuracy, Precision, and %Error

34. Warm up: Precision and Accuracy.
Define precision. Define accuracy.
Describe each situation. Is it accurate? precise? Both?

35. Accuracy
measure of how close a measurement comes to the actual or true value of whatever is measured

36. Precision
measure of how close a series of measurements come to one another

37. Precision and Accuracy

38. Accuracy and Precision

39. Accuracy and Precision

40. Accuracy and Precision
Basketball free throws
99/100 shots are made
99/100 shots hit the rim
33/100 shots are made

41. Accepted vs. Experimental
accepted value = the correct value based on reliable references
experimental value = what was measured in the lab

42. Percent Error
(Accepted – experimental) /accepted value x 100

43. Accuracy and Precision
Density Experiment
A: 2.00, 1.99, 2.01g/mL
B: 2.50, 2.70, 2.90 g/mL
Accepted value: 2.70g/mL

44. Scientific Notation

45. Avogadro’s Number 602000000000000000000000 atoms in 1 mole of Carbon
Mass in Grams of 1 atom of Gold g

46. Scientific Notation
In scientific notation, numbers are written in the form M x 10n, where the factor M is a number greater than or equal to 1 and less than 10 and n is a whole number

47. Step 1
Determine M by moving the decimal point in the original number to the left or the right so that only one nonzero digit remains to the left of the decimal point

48. Step 2
Determine n by counting the number of places that you moved the decimal point. If you moved it to the left, n is positive. If you moved it to the right, n is negative

49. Addition and Subtraction
Addition and Subtraction can be performed only if the values have the same n factor

50. Addition and Subtraction
The n values can be made the same by moving the decimal point of the smaller number

51. Addition and Subtraction
Once the n values are equal, the M value can be added or subtracted and the n factor remains the same

52. Multiplication
In Multiplication the M factors are multiplied, and the exponents are added

53. Division
In Division, the M factors are divided, and the exponent of the denominator is subtracted from that of the numerator

54. Uncertainty and Significant Figures

55. Significant Figures
in measurement include all the digits that are known plus a last digit that is estimated. This last digit that is estimated is uncertain

56. Uncertainty of a Measuring Device
take the smallest space and cut it in half

57. Uncertainty of a Measuring Device

58. Uncertainty of a Measuring Device

59. Figure UNEOC
Title:
Visualizing Concepts 1.6 (a)
Caption:
What is the length of the pencil in the figure if the scale reads in centimeters? How many significant figures are there in this measurement? [Section 1.5]
Notes:
Keywords:

60. Uncertainty of a Measuring Device

61. Counting Significant Figures
Every nonzero digit in a reported measurement is assumed to be significant
There are infinite sig figs when you are counting or dealing with exact quantities

62. Significant Figures
There are infinite sig figs when you are counting or dealing with exact quantities

63. Rule for Determining Significant Zeros
Rule 1: Zeros appearing between nonzero digits are significant

64. Rule for Determining Significant Zeros
Rule 2: Zeros appearing in front of all nonzero digits are not significant

65. Rule for Determining Significant Zeros
Rule 3: Zeros at the end of a number and to the right of the decimal point are significant

66. Rule for Determining Significant Zeros
Rule 4: Zeros at the end of a number but to the left of the decimal point are not significant unless……

67. Rules for Rounding Numbers
Rule 1: If the digit following the last digit to be retained is equal to or greater than 5 then the last digit should be increased by 1

68. Rules for Rounding Numbers
Rule 2: If the digit following the last digit to be retained is less than 5 then the last digit should stay the same

69. Significant Figures
In general, an answer cannot be more precise than the least precise measurement from which it was calculated.

70. Addition or Subtraction
When adding or subtracting decimals, the answer must have the same number of digits to the right of the decimal point as there are in the measurement having the fewest digits to the right of the decimal point

71. Addition or Subtraction
When working with whole numbers, the answer should be rounded so that the final digit is in the same place as the leftmost uncertain digit.

72. Multiplication and Division
For multiplication or division, the answer can have no more significant figures than are in the measurement with the fewest number of significant figures .

73. The End