1. Science Skills and Safety
Scientific Literacy
Science Lab Safety
WHMIS, MSDS, HHPS
Observations vs. Inferences
Significant Digits/Figures
Scientific Notation
The Scientific Method
Metric Conversions

2. Scientific Literacy
Charlatans - a person who falsely pretends to know or be something in order to deceive people

3. Scientific Literacy
What is Scientific Literacy? Look it up.

4. Scientific Literacy
Scientific literacy helps people to understand and evaluate information relating to science and technology in the world so that they make better decisions
A general understanding of science is necessary to be an informed citizen
Why?
Specific scientific knowledge and skills are necessary for a wide range of careers
Like?

6. Science Lab Safety

7. Safety Video

8. Safety Challenge
Look at the picture given to you and list as many unsafe features of the lab as you can.

10. Lab Safety Handout

11. WHMIS Stands for Workplace Hazardous Material Information System
The purpose of WHMIS is hazard identification and product classification, labeling, material safety data sheets, and worker training and education

12. WHMIS Symbols

13. MSDS Stands for Material Safety Data Sheet
Are available for all used chemicals and contain important information

14. Sodium MSDS handout

15. HHPS Stands for Hazardous Household Product Symbols
Found on virtually all potentially dangerous household products
Indicates both the type of danger and the degree of risk

16. Hazardous Household Product Symbols

17. All Possible HHP Symbols
Poisonous
Flammable
Explosive
Corrosive
Danger
Warning
Caution

18. Prevent it – Safety Video

20. Observations and Inferences

21. OBSERVATIONS AND INFERENCES
Observation: statement of facts and occurrences that are made using our senses and sometimes by measurement with scientific instruments.
e.g. The surface of the lab. benches around the perimeter of the room are black and shiny.
The temperature of your grade 9 teacher’s coffee is 80oC.
Your own examples

22. OBSERVATIONS AND INFERENCES
Inference: statement based on reasoning from observations made.
e.g. The benches surfaces are probably smooth and cold ( based on seeing them black and shiny )
The teacher’s coffee looks hot ( based on seeing steam rising from the cup )
Your own examples

23. Try It Give 2 observations from the picture.
2. Give 2 inferences from the picture.

25. Significant Digits (Figures)

26. Significant Digits (Figures)
Significant digits represent the amount of uncertainty in a measurement. Any digit that is actually measured or estimated will be considered significant.
E.g. The length of something is between 5.2 and 5.3 cm. Suppose we estimate it to be 5.23 cm.

27. Significant Digits
The first 2 digits (5 and 2) are certain but the last digit (0.03) was estimated. Therefore, the measurement 5.23 has three significant digits.

28. Significant Digits Rules
All non-zero digits (1-9) are considered significant.
e.g. 123 m=3 s.d., 23.56=4 s.d.

29. Significant Digits Rules
2) Zeros between non-zero digits are also significant. e.g m = 4 s.d., km/h = 4 s.d.

30. Significant Digits Rules
3) Any zero that follows a non-zero digit and is to the right of the decimal point is significant. e.g m/s = 4 s.d. because it shows that we actually measured that digit to be km = 4 s.d.

31. Significant Digits Rules
4) Zeros used to indicate the position of the decimal are not significant. e.g. 500 km = 1 s.d., m = 3 s.d., km = 2 s.d.

32. Significant Digits Rules
5) All counting numbers have an infinite number of significant digits because we are certain of the exact number e.g. 6 apples = infinite s.d.

33. Significant Digits

34. Homework
Significant Digits Worksheet

36. Scientific Notation

37. How far away is the nearest Star besides our Sun (Proxima Centauri)?
km (13 zeros) This number is written in decimal notation. When numbers get this large, it is easier to write them in scientific notation.

38. Scientific Notation
A number is expressed in scientific notation when it is in the form
a x 10n
where a is between 1 and 10
and n is an integer (neg. and pos. whole number)

39. Write the distance to Proxima Centauri in scientific notation.
km Where is the decimal point now? After the last zero. Where would you put the decimal to make this number be between 1 and 10? Between the 4 and the 0

40. 4.0,000,000,000,000.
How many decimal places did you move the decimal? 13 When the original number is more than 1, the exponent is positive. The answer in scientific notation is 4.0 x 1013

41. Express 0.0000000902 in scientific notation.
Where would the decimal go to make the number be between 1 and 10? 9.02 The decimal was moved how many places? 8 When the original number is less than 1, the exponent is negative x 10-8

42. Write 28750.9 in scientific notation.
x 10-5
x 10-4
x 104
x 105

43. Example Given: 289,800,000 Use: 2.898 (moved 8 places)
Answer: x 108

44. Example
Given:
Use: 5.67 (moved 4 places)
Answer: 5.67 x 10-4

45. Write in PROPER scientific notation
Write in PROPER scientific notation. (Notice the number is not between 1 and 10)
234.6 x 109
2.346 x 1011
2) x 104
6.42 x 102

46. Write 531.42 x 105 in scientific notation.

47. We can also go the other way
Express 1.8 x 10-4 in decimal notation Express 4.58 x 106 in decimal notation. 4,580,000

48. Example
Given: x 106
Answer: 5,093,000 (moved 6 places to the right)

49. Example
Given: x 10-4
Answer: (moved 4 places to the left)

50. Significant Digits and Scientific Notation
When trying to determine the number of significant digits within scientific notation we leave it the way it is and follow the same rules and pretend the x 10n is not there.
E.g.
x10-4 has 4 significant digits
5.3x1015 has 2 significant digits

51. Try These
1) x 10-4  answer in proper scientific notation to 3 significant digits
= 1.46 x 10-5
2) x 105  answer in proper scientific notation to 3 significant digits
= 4.57 x 102

52. Homework Scientific Notation and Sig Digs Worksheet 1 and Answers
Scientific Notation Significant Digits Worksheet 2 and Answers

54. The Scientific Method

55. The Scientific Method

56. The Ten Steps of the Scientific Method
Questioning
Controlling Variables
Making a hypothesis
Planning
Performing
Observing
Analyzing
Discussing
Concluding
Communicating

57. 1) Introduction & Question
Relevant observations, inferences, background knowledge is provided
Similar to brainstorming
Question
Semi-formal
Question should interest you
Question can be about anything
E.g. Are taller people better at basketball than shorter people?

58. 2) Controlling the variables
Variables are factors that can affect the outcome of an investigation:
1) Independent variable – variable that is changed
2) Dependent variable – variable that is affected by the independent variable
3) Controlled/Standardizing variable – variable that remains unchanged and does not affect the outcome
4) Control Group – Group that is not changed, normal conditions  used to compare results

59. Try It
1) An archer tests a bow by seeing how tightening the bow changes how far the arrow can be launched.
Independent variable is :
Dependent variable is :
2) A student experiments to see if the length of a pendulum affects how fast it swings.
3) A boy tries on different running shoes to see how much each one slides on ice.

60. Practice
Patty Power Mr. Krabbs wants to make Bikini Bottoms a nicer place to live. He has created a new sauce that he thinks will reduce the production of body gas associated with eating crabby patties from the Krusty Krab. He recruits 100 customers with a history of gas problems. He has 50 of them (Group A) eat crabby patties with the new sauce. The other 50 (Group B) eat crabby patties with sauce that looks just like new sauce but is really just mixture of mayonnaise and food coloring. Both groups were told that they were getting the sauce that would reduce gas production. What is the independent variable? _________________________ What is the dependent variable? _________________________ Which people are in the control group? _________________________

61. Variables Worksheet 1

62. 3) Making a hypothesis
A Hypothesis is a tentative answer about the outcome of an experiment
Should be presented in an “if / then statement
Should indicate cause and effect relationship for your dependent and independent variables
Can usually be derived directly from your original question
Is an educated guess
Should be only a single sentence
Must be feasibly testable
“IF the independent variable changes in some way THEN it will affect the dependent variable in some way.”
E.g. If someone is taller then they will be better at basketball.

63. Create a hypothesis for each of the following
1. Human age and the chance of getting a heart attack. Hypothesis: 2. Skin cancer and the amount of UV light. Hypothesis: 3. Leaf colour change and temperature. 4. Amount of sleep per night and student test scores. Hypothesis:

64. 4) Planning Identify all your variables
Consider equipment and materials
Make a materials list using bullet points
Write a clear procedure

65. Writing a procedure
A procedure is a sequential list of steps that are to be followed exactly during an experiment. Steps should be in order and numbered.
Hints: Be specific, be exact, watch your language.
Try this:
In a group of 2, write up a procedure for washing your hands. Starting from dry hands and ending with dry hands.

66. 5) Performing the experiment
Follow procedures exactly, if procedures are unclear ask
Be safe
Record which variables are being changed and how they are being changed
Repeat experiment a minimum of three times. (Why?)
Make careful notes of everything that occurs during your experiment, in addition to the data filling in charts and tables. Note possible sources of error

67. 6) Observing and recording data
Record all data/observations in an appropriate form. (Charts or tables are most common)
Record all data as clearly and accurately as possible
Make careful notes of everything that occurs during your experiment.
Note possible sources of error in the experiment

68. 7) Analyzing results
When possible create graphs to represent numerical data, as it is easer to read and understand for others
Each table and graph contains a caption (i.e. Table 1, Figure 1 (graphs), etc.)
Identify patterns and trends in results
Make conclusions
State what occurred/was found by referring to the tables and graphs (i.e. “According to Figure 1…”)
Do not discus the results, just state them.

69. Graphing Rules for Good Graphing
1. Always give your graph a title in the following form: "The dependence of (your dependent variable) on (your independent variable)”.
Let's say that you're doing a graph where you're studying the effect of temperature on the speed of a reaction. In this reaction, the speed will depend on the temperature – therefore, speed is the dependent variable and temperature is the independent variable.
As a result, the title of your graph will be "The dependence of reaction rate on temperature",
2. The x-axis of a graph is always your independent variable and the y-axis is the dependent variable. For the graph described above, temperature would be on the x-axis (the one on the bottom of the graph), and the reaction rate would be on the y-axis (the one on the side of the graph)

70. 3. Always label the x and y axes and give units. E. g
3. Always label the x and y axes and give units. E.g. temperature on the x-axis would be – Temperature (°C). On the y-axis you would put – Time (s).
4. Make a line graph unless told otherwise but don’t connect the dots.
5. Most of the time, you do not connect the dots on your graph! Instead, do a line of best fit which can be straight or curved but doesn’t go from one dot to another.
6. Make sure your data is graphed as large as possible in the space you've been given.

71. Examples of Graphing Let's see what's wrong with this graph:
There's no title.
There are no labels on the x or y axis.
There are no units on the x or y axis.
The dots are connected.

72. GRAPHING RULES CHECKLIST
All graphs made in this course must meet the requirements outlined in the following checklist. 1. Graph paper is used for all graphs ( not lined or plain paper ). 2. Your name and date are to be printed at the top right corner of the page. 3. The axes should be spread out enough to fill at least 2/3rds of the available space. 4. Title - located above the graph - written in pen - underlined - provides information that relates the dependent variable to the independent variable 5. Axes labels - written in pen - name of variable with units in brackets e.g. mass (kg) 6. Scale – written in pencil - equal mathematical intervals for equal grid squares - horizontal and vertical axes do not necessarily have to be the same scale 7. Points – plot using either ‘ X ’ through the point or circle the point 8. Line of best fit - usually a straight line through at least two plots with equal # of plots above the line and below the line

73. Determine if the axis are labelled correctly or if they are reversed

74. Check your answers

75. 8) Discussion Results are discussed and interpreted
Sources of error are identified, discussed in terms of how the results could have been affected, and suggestions of how to improve if the experiment was repeated
do not say human error
be specific
Written in past tense and 3rd person.

76. 9) Conclusion 10) Communicating Hypothesis is restated
Results are summarized
State whether hypothesis is accepted or rejected
10) Communicating
Share your process and finding with others by writing a report

77. **ALL MUST BE DONE IN PAST TENSE AND IN THE THIRD PERSON**
Your Lab Reports
Introduction: Topic/issue overview and Question
Hypothesis:
Variables:
Materials:
Procedure:
Results: State what was found by referring to graphs and tables
Discussion:
Conclusion:
**ALL MUST BE DONE IN PAST TENSE AND IN THE THIRD PERSON**

78. Writing your report There should be no:
I, We, Our found within your lab report!
E.g. The mouse was placed in the maze not, We placed the mouse in the maze.

80. Metric Conversions

81. Metric and Unit Conversions
Metric and Unit conversions are necessary in science since results within experiments may be measured using different equipment. In order to accurately compare results, it is important that we ensure that the units on the measurements match up.
Also, at times it is not practical to use certain units to determine certain quantities  e.g. long distances in cm.

82. How it works How many millimetres are in 3.5 metres?
We have 3.5 metres
We want millimetres

83. Conversions (1st Way) How many mm are in a m? Answer: 1000 mm = 1 m
How many mm are in 3.5 m?
? mm = 1000mm multiply both sides by 3.5m
3.5m m
? mm (3.5m) = 1000mm (3.5m)  ? = mm
3.5m m
Therefore there are 3.5 m in mm

84. Conversions (1st Way) How many cm are in 2.45 m? 100 cm = 1 m
?cm = 100 cm multiply both sides by 2.45m
2.45m m
? mm (2.45m) = 100cm (2.45m)  ? = 245 cm
2.45m m
Therefore there are 245 cm in 2.45 m

85. Conversions
Metric Conversions worksheet
Answer the problems provided