2. What is Chemistry?
Chemistry is: the study of matter & the changes it undergoes
Composition
Structure
Properties
Energy changes

3. Taking Measurements

4. Le Systeme International d’ Unites or SI System
The SI System
Around 1793, scientists all over the world began to agree upon a single measurement system called
Le Systeme International d’ Unites or SI System
7 base units
The idea was to create a unifying system of weights and measurements

5. This is the SI standard unit but the BASE unit is the GRAM
Quantity
Unit
Symbol
Mass
kilogram kg
Length
meter m
Time
second s
Amount of Substance
mole
mol
Temperature
Kelvin K
Electric current
Ampere A
Luminous intensity
candela cd
Note:
This is the SI standard unit but the BASE unit is the GRAM
Crash Course: Units
Where’s volume??
What’s missing?

6. Derived Units Combinations of base units
Volume: amount of space taken up by an object
Most common unit: cm3 = mL
Density: ratio of mass to volume
Common units: g/cm3 of g/mL or g/L
Does not change for a given substance

7. Prefix
Symbol
Meaning
Numerical Value
Giga- G
109
1,000,000,000
Mega- M
106
1,000,000
Kilo- k
103
1,000
Hecto- h
102
100
Deka da
101 10
BASE
g, l, m 1
Deci- d
10-1 .1
Centi- c
10-2
.01
Milli- m
10-3
.001
Micro-
10-6
Nano- n
10-9

9. 5.6 cm to m 56 mg to g 340 mm to cm 1.2 ML to L Practice Problems

10. Scientific Notation
Some numbers are very large or very small, so a short hand notation is needed!
Too large:
602,000,000,000,000,000,000,000
6.02 x 1023
Too small:
1.99 x 10-23

11. General Notation: N x 10n N is a number between 1 and 10
n is a positive or negative integer
if n is a negative number, the full number is a small decimal
if n is a positive number, the full number is a large number

12. Practice
3.69 x x x x x x 102

13. Factor-Label Method (Dimensional Analysis)
Solve the following mathematical equation:
1 2 x x x x x x x =
𝑚𝑖𝑙 ℎ𝑟 x ℎ𝑟 𝑚𝑖𝑛 x 𝑚𝑖𝑛 𝑠𝑒𝑐 x 𝑘𝑚 𝑚𝑖𝑙 x 𝑚 𝑘𝑚 =

14. Using Factor-Label Method
Sample Problems:
Converting 9.8 g to kg
9.8 g    x   1 kg        = kg               g  
Converting 9.8 kg to g
9.8 kg    x   g        = 9800 g                   1 kg
“1” goes in front of larger unit!

15. Density Practice
Density Formula
D = m V m D V

16. Measuring always involves some estimation
Certain Digits: A digit that represents a mark on a scale or a non-blinking number on a display.
Uncertain (Estimated) Digits: A digit that represents the space between the marks on a scale or a blinking number on a display.
what is certain?
what is uncertain?

17. Making Measurements

18. Sig Figs: Using the Pacific/Atlantic Rule
Step 1: Ask yourself: is the decimal point Present or Absent?
Step 2: Determine which way to start counting
If the decimal point is Present, start counting from the LEFT
If the decimal point is Absent, start counting from the RIGHT A T L N I C
bsent P A C I F
resent

19. Pacific/Atlantic Rule
Step 3: Start counting on Pacific or Atlantic side from the first NON-ZERO number. Count all numbers after the first non-zero number including zeros.
Examples:
1234 = ________ sig figs
1204 = ________ sig figs
= _______ sig figs
1230 = ______ sig figs
= ______ sig figs
Absent 
Absent 
Present 
Absent 
Present 

20. Using Sig. Figs. In Calculations
Addition/Subtraction Rule
Answer should contain least # of decimal places
Multiplication/Division Rule
Answer should contain least sig figs.

21. Do Now: Precision of Lab Instruments
Record the following quantities to the correct number of decimal places.
________ L ________ mL _______ oC
Convert your answer in A to milliliters: ________ mL
Add your answer from A & B. Record using correct sig. figs ________ mL

22. Analyzing Measurements

23. Accuracy & Precision in Measurements
Accuracy: closeness of measurements to correct value
Precision:
closeness of a set of measurements to each other (assuming they’re made in the same way)
When recording a measurement, an instrument that provides the most digits past the decimal is most precise.

25. Accuracy vs. Precision
Example: A student measures the density of a sample of nickel.
The density of nickel is g.mL -1
Is this accurate or precise?
Density Result (g.mL -1)
Trial 1
7.8
Trial 2
7.7
Trial 3

26. % Error = Experimental – Accepted x 100
Percentage Error
Accuracy of an individual value (or average) can be compared to the correct/accepted value
% Error = Experimental – Accepted x 100
Accepted

27. Percentage Error
What is the percentage error for a mass measurement of 17.7 g, given that the correct value is 21.2 g?
A volume is measured experimentally as mL. What is the percentage error, given that the accepted value is 4.15 mL?

28. Scientific Method

29. logical approach to solving problems
SCIENTIFIC METHOD
logical approach to solving problems
Observation
Problem
Hypothesis
Experiment
Data
Analysis
Conclusion

30. You have 15 seconds to count how many letter “F”s you see in the following statement.

31. FEATURE FILMS ARE THE RESULT OF YEARS OF SCIENTIFIC STUDY COMBINED WITH THE EXPERIENCES OF YEARS.

32. Types of Observations
Qualitative (think “quality”): observations using words Example:
Quantitative (think “quantity”): observations using numbers and units. Example:

33. How observant are you?!?

34. PHYSICAL AND CHEMICAL CHANGES

35. Physical Properties and Changes
physical property: characteristic that can be observed or measured without changing the identity of the substance.
melting point, boiling point, density
physical change: change in a substance that does not involve a change in the identity of the substance.
dissolving, cutting, melting, and boiling

36. Chemical Properties and Changes
chemical property: a substance’s ability to undergo changes that transform it into different substances
Example: combustibility, reactivity
chemical change: change in which one or more substances are converted into different substance
Example: rusting, cooking food

37. Evidence of a Chemical Change
Color change
Temperature change
Production of a gas
Change in odor
Formation of a precipitate
Precipitate: insoluble solid that separates out of solution

38. Solubility and Phase changes are PHYSICAL!!!!
NOTE:
Solubility and Phase changes are PHYSICAL!!!!

39. In an experiment…
System: specific portion of the experiment that has been selected for study
Constant: experimental conditions that do not change
Control: experimental condition that is used as a standard for comparison
Variable: experimental condition that does change

40. SpongeBob loves to garden and wants to grow lots of pink flowers for his pal Sandy. He bought a special Flower Power fertilizer to see if it will help plants produce more flowers. He plants two plants of the same size in separate containers with the same amount of potting soil. He places one plant in a sunny window and waters it every day with fertilized water. He places the other plant on a shelf in a closet and waters it with plain water every other day.
1. What are Spongebob’s constants in his experiment? 2. What are Spongebob’s variables in his experiment? 3. What did Spongebob do wrong? 4. What should SpongeBob do to test the effectiveness of Flower Power fertilizer? Describe an experiment.

41. Amount of Fertilizer (g)
Plant Growth (cm) 6 5 9 15 17 23 22
Independent Variable
Dependent Variable
Fertilizer Growth
Direct Relationship
Title
Appropriate scale
Axis labeled
“Best fit” line

42. Direct Relationships
When 2 quantities divided by each other gives a constant value
K (constant value) = Y/X
Ex: Density

43. Inverse Relationships
When 2 quantities multiplied by each other gives a constant value
K = X Y
Ex: Boyle’s Law
K = PV