1. Units of Measurement Base Units Derived Units Length meter (m) Volume
SI units (Systeme Internationale d’Unites) were developed so that scientists could duplicate and communicate their work.
A unit that is defined by a combination of a base units.
Base Units
Derived Units
Length
meter (m)
Volume
meter cubed (m3)
Mass
kilogram (kg)
Density
grams per cubic centimeter (g/cm3)
Time
second (s)
Temperature
kelvin (K)

2. Units of Measurement

3. Metric Conversions
Move the decimal to the right
Move the decimal to the left
Every metric unit is different from its neighbor by a factor of ten
When converting between two units the decimal point is moved the number of places equal to the distance between the two unit in the chart above and in the same direction of movement

4. Sample problem Convert the following Start with 53.
Move the decimal to the right
Move the decimal to the left
Convert the following
53 hg = ________dg
Start with 53.
Move the decimal 3 spaces to the right 53
Fill in the empty spaces with zeros dg

5. Sample Problem Start with 300.
Move the decimal to the right
Move the decimal to the left
Convert the following
300 cg = ________kg
Start with 300.
Move the decimal 5 spaces to the left
Fill in the empty spaces with zeros kg

6. More Practice Problems
Convert the following
0.058 dam = _______ dm
0.25 cL = _______ L
109 hg = ________ mg
5.8
0.0025

7. Units of Measurement Derived Units…
A unit that is defined by a combination of base units is called a derived unit.
Volume: the space occupied by an object.
The metric unit for volume equal to one cubic decimeter (dm3) is a liter (L).
Density: a ratio that compares the mass of an object to its volume.
The units for density are often grams per cubic centimeter (g/cm3).
Formula –

8. Density Ratio of an object’s mass to its volume
What happens to density when mass is constant and volume changes?

9. Mass, Volume and Density Relationships
DIRECT
INDIRECT

10. Density Problem Example…
Suppose a sample of aluminum is placed in a 25-ml graduated cylinder containing 10.5 ml of water. The level of the water rises to 13.5 ml. What is the mass of the aluminum sample if its density is 2.70 g/ml?
FORMULA _______________
NEW FORMULA _______________
PLUG-IN NUMERICAL VALUES (with units)
SOLVE (answer)

11. Temperature Scales Temperature…
The temperature of an object is a measure of how hot or cold the object is relative to other objects.

12. Homework #1
Page(s) 30
Problem(s): 4, 5, 6, 10, and 11

13. What is the significance of this number?
Pre-Class Activity
What is the significance of this number?
How would you express this number in scientific notation?

14. Scientific Notation 6.02 x 1023 Exponent Coefficient
The coefficient must be greater than or equal to one and less than 10.
When expressing numbers less than one (ex ) in scientific notation, the decimal point is moved to the right until the coefficient is within range. The number of spaces moved is used to determine the exponent.
For numbers less than one, the exponent is negative
When expressing numbers greater than 10 (ex. 1000) in scientific notation, the decimal point is moved to the left until the coefficient is within range. The number of spaces moved is used to determine the exponent.
For numbers greater than 1, the exponent is positive.

15. Scientific Notation Calculations
Multiplication and Division
For multiplication, multiply the coefficients and add the exponents
(1.3 x 104) x (2.0 x 106) =
Remember, your final answer must be in the correct form. Often, multiplication of coefficients will yield a number greater than 10. In this case the result must be changed into the proper form.
(5.3 x 104) x (2.0 x 106) = =
For division, divide the coefficients and subtract the exponents. Often, division of coefficients will result in a value that is less than one. If this occurs, the final result must be changed into the proper form.
(2.0 x 10-3)  (4.00 x 104) = =
2.6 x 1010
10.6 x 1010
1.06 x 1011
0.5 x 10-7
5 x 10-8

16. Scientific Notation Calculations
Addition and Subtraction
In order to add or subtract numbers in scientific notation, the exponents of each number has to be the same
As a rule of thumb, it is best to take the number with the lower exponent and change it match the higher exponent.
To increase an exponent, move the decimal point in the coefficient to left, the number of spaces equal to the increase in the exponent.
Once the exponents are equal, the coefficients can be added or subtracted
2.1 x 104
x 103
2.1 x 104
x 104
2.2 x 104
5.37 x 10-4
x 10-5
5.37 x 10-4
0.62 x 10-4
4.75 x 10-4

17. Homework #2
Page(s) 32-33
Problem(s): 13, 14(a-d), 15(a, b), 16(a, b)

18. Factor Label Method of Conversion
100 cm = 1 m
1 m = 100 cm
Use conversion factors to systematically move from one unit to the next, cancelling out units on the diagonal in each step.
Convert
18 m = _______ cm
100 cm
18m
= 1800 cm
1 m

19. Multistep Factor Label Problems
Convert
350 tsp = ______ L
Using the following conversion factors
1 tsp = 5 mL
1 L = 1000 mL
5 mL
1 tsp
1 L
1000 mL
350 tsp
= 1.75 L

20. Multistep Factor Label Practice
Convert 3 min= ______ms
Use 1 min=60 s and 1000 ms = 1 s
Convert 32oz = _____ g
Use 16 oz=1 lb, 2.2 lb = 1kg, 1kg=1000 g

21. Multidimensional Factor Label Problems
Convert 25 g/mL = ______ kg/dL
Convert one unit at a time
Recognize that one unit is in the denominator
25 g
1 mL
1 Kg
100mL
1 dL
=2.5kg/dL
1000 g

22. Multidimensional Factor Label Practice
Convert 85 km/hr = _________m/s
Convert 0.6 L/min = ________ qt/hr
Use 1qt = 1.1L

23. 1 ft = 12in Factor Label Practice for Area and Volume
Remember to square or cube the unit as well as the number when converting to a squared or cubed unit
1 ft = 12in

24. Homework #3
Page(s) 34-35
Problem(s): 17 and 21

25. Pre-class Activity
How long is this paperclip? To what degree of certainty can it be measured?

26. Significant Figures in Measurement
Scientists determine the precision of instruments by the number of digits they report.

27. Significant Figures in Measurement
Measurements always include all certain digits and one uncertain digit.
52.7 mL

28. Measurement Challenge
What value would you assign to each of these measurements?
_________ mL
_________ cm

29. Identifying Significant Figures in Numbers
When examining a number, you determine the number of digits that are significant by the following rules:
All non-zero numbers are significant
All final zeros to the right of a decimal are significant
Zeros between significant digits are significant
For positive numbers less than one, all zeros directly after the decimal before the first significant figure are not significant.
All zeros at the end of a whole number are not significant.
All contants and counting numbers have an unlimited number of significant figures. 4. 5.

30. Sig Fig Challenge
How many sig figs are there in the following numbers:
0.0004
687
1.0082
330

31. Sig Fig Rules for Calculations
Multiplication and Division
Your answer can not contain more or less sig figs than the operator that contains the least number of sig figs.
3.86 x 0.45=1.737
1.7
1.737
Identify the significant figures, look on place beyond. If that digit is 5 or above, round up. If it is less than 5 drop off.

32. Sig Fig Rules for Calculations
Addition and Subtraction
Your answer can not be more precise than the least precise operator. Most of the time this means that your answer must have the same number of decimal places as the least precise operator
12.38 cm cm
14.88 cm cm cm cm
cm cm
If one of the numbers is a whole number that ends in zero(s), then the final answer must be rounded to the lowest place that contains a nonzero number.

33. Reliability of Measurements
Accuracy vs. Precision
How close a measured value is to an accepted value
How close a series of measurements are to one another
High Accuracy
High Precision
Low Accuracy
High Precision
Low Accuracy
High Accuracy

34. Percent Error
Used to evaluate the accuracy of experimental data.

35. Homework #4
Page(s) 38-42
Problem(s): 29, 31, 33, 35, 37(a, b), 38(a, b)

36. Representing Data Graphing Circle Graphs (based on percents)
Bar Graphs (How quantities vary)

37. Graphing continued Line Graphs
In science, we draw a best fit line between data points.
Do not connect the dots.
Dependent Variable
Dependent Variable
Independent Variable
Independent Variable
Which graph shows and indirect relationship between the dependent and independent variable?

38. Calculating the Slope of a Best Fit Line
Select two points on the line that you have drawn. Do not select two of your data points because they might not fall on the line.

39. Line Graph Basics Graphing Reminders… Fit the page Graph title
Consistent x-axis and y-axis scales
Labeled (with units) x-axis and y-axis
Best fit line
DO NOT CONNECT THE DOTS!

40. Review Assignment Page 50
Problem(s): 52, 57, 59, 73, 75 (a, b, c, and d), and 76 (a, b, c, and d)
Page 51
Problem(s): 77 (b, d, e, g, h, and i), 78 (a, e, and f), 80 (a, b, c, d, e, and f), 82 (a and c), 84 (c, e, and f), 85 (a, b, c, and d), and 86 (a, b, c, and d)
Page 52
Problem(s): 87
Page 53
Problem(s): 1, 3, 5, 7, and 9