1. Scientific Measurement
Chapter 3
Scientific Measurement

2. Ch 3.1 The Importance of Measurement

3. Ch 3.1 The Importance of Measurement
Qualitative Measurement – measurement that gives descriptive nonnumeric results
Example: Feel some ones head to see if they are running a fever or not
Quantitative Measurement – measurement that gives definite usually numeric results
Example: Measure some ones temperature with a thermometer

4. Scientific Notation Used to write small or large numbers N x 10n
N = a number between 1 and 10
n = a positive or negative integer

5. Scientific Notation Mass of an atom of gold
3.27 x 10-22g
Number of hydrogen atoms in 1g
6.02 x 1023 atoms

6. Coefficient
Scientific notation has three parts to it: the coefficient, base, and exponent

7. Scientific Notation: Multiply and Divide
Multiply coefficients and add exponents
(3.0 x 104) x (2.0 x 102) = 6.0 x 106
Divide coefficients and subtract exponents
(3.0 x 104) / (2.0 x 102) = 1.5 x 102

8. Scientific Notation: Addition and Subtraction
Make the exponents the same, then add or subtract
3.0 x x 102 =
300.0 x x 102 = x 102

9. Chapter 3.2 Uncertainity

10. Accuracy and Precision
Accuracy – how close a measurement is to the true value of the quantity measured
Precision – how closely two or more measurements of the same quantity agree with one another

14. Accuracy and Precision
A student was asked to measure the length of the hallway. He came up with the following lengths.
10.2m, 10.1m, 10.2m
The actual length was 12.5m.
How would you describe his results?

15. Accuracy and Precision
A student was asked to determine the mass of a beaker. She came up with 34.8g, 34.7g and 34.7g.
The actual mass was 34.8g.
How would you describe her results?

16. Percent Error % Error = accepted value – experimental value x 100
The correct answer
Your answer
The correct answer

17. Percent Error
A student was asked to determine the mass of a beaker. She came up with an average mass of and 34.7g.
The actual mass was 34.8g.
What is the percent error?
34.8 g –34.7 g x 100 = % Error
34.8

18. Significant Figures Abbreviation: sig fig
Why are sig figs so IMPORTANT?

19. Significant Figures 1) Any digit that is not zero is significant
24.7 meters 3 sig figs
0.743 meters 3 sig figs
74 grams 2 sig figs

20. Significant Figures 2) Zeros between nonzero digits are significant
7003 mL 4 sig figs
40.7 cm 3 sig figs
g 5 sig figs

21. Significant Figures
3) Zeros to the left of the first nonzero digits are not significant
km 2 sig figs
0.420 g sig figs
L 4 sig figs

22. Significant Figures
4) If a number is greater that 1, then all the zeros written to the right of the decimal point count as significant
43.00 m 4 sig figs
mg 5 sig figs
9.00 cL 3 sig figs

23. Significant Figures
5) Numbers without a decimal, the trailing zeros may or may not be significant. It will depend on other information in the problem.
5, or 4 sig figs
68, or 5 sig figs
52,010, or 8 sig figs

24. Significant Figures 6) Unlimited significant figures when:
- Counting an exact number (whole number only) such as number of people in the class
- Exactly defined quantities
60 minutes = 1 hour

25. Significant Figures for Calculations
Addition and Subtraction: The answer can not have more digits to the right of the decimal point than either original number. (Least number of decimal places) =
421.6
– =
20.422
20.42

26. Significant Figures for Calculations
Multiplication and Division: The number of significant figures in the final product or quotient is determined by the original number with the smallest number of significant figures.
12,003 x 45 = 1,525÷ 30.1 =
540,
540,

27. Chapter 3.3 SI Units International System of Units From the French:
Le Systeme International d’Unites

28. energy, work, quantity of heat
SI Units
Symbol
Name
Quantity m
meter
length g
gram
mass Pa
pascal
pressure K
kelvin
temperature
mol
mole
amount of a substance J
joule
energy, work, quantity of heat s
second
time

29. solution concentration
SI Units (continued)
min
minute
time h
hour d
day y
year L
liter
volume
ppm
parts per million
concentration M
molarity
solution concentration u
atomic mass unit
atomic mass

30. Prefixes with SI Units Prefix Symbol Meaning tera- T
1,000,000,000,000 or 1012
giga- G
1,000,000,000 or 109
mega- M
1,000,000 or 106
kilo- K
1,000 or 103
hecto- H
100 or 102
deca- D
10 or 101
BASE
m, L, g, ….
Any base unit
deci- d
1/10 or 10-1
centi- c
1/100 or 10-2
milli- m
1/1,000 or 10-3
micro- μ
1,000,000 or 10-6
nano- n
1,000,000,000 or 10-9
pico- p
1,000,000,000,000 or 10-12

31. How to remember the basic metric prefixes?
Mnemonics :These stand for the Metric prefixes and base unit.
kilo hecto deca base deci centi milli
Kittens Hate Dogs Because Dogs Cant Meow
Kangaroos Hop Down My Driveway Christmas Morning
Kings Hate Dragons Because Dragons Can’t Make Money
King Henry Died Bloated Drinking Chocolate Milk
Kangaroos Hop Down Mountains Drinking Chocolate Milk

32. giga mega kilo hecto deca BASE deci centi milli micro nano pico
King Henry Danced Merrily Down Center Main Meeting Nice People
Great Mighty King Henry Died By Drinking Chunky Milk
Good Models Know How Dunkin Donuts Can Make U Not Petit

34. Chapter 3.4 Density Density = Mass / Volume d = m/v 1 g/cm3 = 1 g/ml
1 mL = 1 cm3

35. Density Column

37. Chapter 3.5 Temperature Scales
0C = K – 273
K = 0C + 273
Freezing
00C = 273K
Boiling
1000C = 373K
Absolute Zero
O K

38. Temperature Scales