1. Chemistry
Matter and Change

2. What is Chemistry All About?
How does this photo illustrate what chemistry is all about??
Chemical reactions of rusting/weathering/maybe a fire in the fireplace
Physical states of water
Different types of materials: glass, wood, living material, brick, snow

3. The Study of Matter and Change
What is Matter?
Anything that has mass and takes up space (volume)
Not Matter
Light
Energy
Emotions or Feelings
Thoughts
Electricity
Sound

4. Pure Science Vs Applied Science
Pure Science: For the sake of the knowledge
Studying butterflies just to know more
Researcher lives on a remote island to daily study the jungle trees
Studying ape behavior
Applied Science: Using science to solve a particular problem
Scientist studying corn in fields to increase the yield for farmers
Scientist searching for a cancer cure

5. Why is Pure Research Important?
A Base of knowledge when needed
Keeps us current
General not specific and possible commercial
Accidental Discoveries

6. Technology Application of Science for human benefit Good and Bad
Nuclear Technology
Good: Energy Bad: Waste
Computer Technology
Good: Communication Bad: Wasted Time

7. Chemistry is traditionally broken into branches that focus on specific areas such as
Organic chemistry
Inorganic chemistry
Physical chemistry
Analytical chemistry
Biochemistry
Environmental chemistry
Industrial chemistry
Polymer chemistry
Theoretical chemistry
Thermochemistry :

8. This Class HS General Chemistry is Inorganic
Inorganic: the study of non-carbon based compounds
Organic Chemistry: Study of matter that contains carbon

9. The Scientific Method
The scientific method is a systematic approach used in scientific study, whether it is chemistry, physics, biology, or another science.
To solve problems
Not a set of rigid steps
It is an organized process used by scientists to do research, and provides methods for scientists to verify the work of others.

10. Observations
Gathering Information (Data) using the five senses
No trivial or unimportant observations
Don’t make inferences or assumptions when you observe
Qualitative data is obtained through observations that describe color, smell, shape, or some other physical characteristic that is related to the five senses.
Quantitative data is obtained from numerical observations that describe how much, how little, how big or how fast.

11. Controlled Experiment
A test of a hypothesis
Making observations under controlled conditions
Where only one variable at a time is changed
Systematic approach to test a hypothesis
Parts of An Experiment
Variables: A condition changed in an experiment
Independent
Dependent
Constants: any factor not changed in an experiment
Control: Group/set up that has no changes made to it
Conclusion: A judgment based on the observations made in a controlled experiment

12. Independent Variable Changed by the experimenter Allowed to change
The Cause in Cause and Effect
Manipulated Variable
Happens First
The water’s temperature increased as more heat was applied.
The temperature of the solid caused the density of the solid to change
An increase in phosphorous helped the plants to grow taller.

13. Dependent Variable
Changes in response to the change in the independent variable
Responding Variable
Happens second
The boiling point increased as salt was added to the water
The hamster grew two inches with an increase in the hormone.

14. Control A point of comparison in an experiment
The group that does NOT receive the treatment

15. Constants
Specifics that remain the same between the control group and the experimental group
Only the independent variable should be changed by the experimenter
Examples of Constants:

16. Conclusion
A conclusion is a judgment based on the information obtained from the experiment

17. Hypothesis and Experiment
Hypothesis: A tentative explanation of observations
A tentative answer
A statement to be tested by an experiment
Example: If I give the fish more hormone then they will grow longer.
Experiment: The test of a hypothesis
A controlled set of steps to test a hypothesis

18. Theory Vs Hypothesis
A theory is a hypothesis that has stood the test of repeated experiments
An explanation of results
Never proven
Can be disproven
All theories are hypotheses . (True)
All hypotheses can become theories. (True)
All hypotheses are theories. (False)

19. Experiment
Kate noticed that she could dissolve more sugar in the tea when it was warm than when it was ice cold. She wondered if this was true for all solids. She decided to design an experiment to see if water temperature effects how much salt can be dissolved.
She chose table salt as her solid to test. She used water as her solvent.
Hypothesis: An increase in the temperature of the water will allow more salt to dissolve,
She placed 100 mL of water in each of mL beakers.
She cooled the water in beaker # 1 to 10 degrees C.
The water in beaker #2 was 25 degrees C.
Beaker # 3 water was heated to 35 degrees C.
Beaker # 4 water was heated to 45 degrees C.
Beaker # 5 was heated to 55 degrees C.

20. Beaker # 6 65 degrees C
Beaker # 7 75 degrees C
Beaker # 8 85 degrees C
Beaker # 9 95 degrees C
Beaker # degrees C

21. She added salt to each beaker while using a magnetic stirrer which provided constant and uniform stirring until no more salt would dissolve.
She measured and recorded the amount of salt that dissolved in each beaker.
Her data is shown below.

22. Data Amount of water 100 mL Temp of Water (degrees C)
Grams of salt dissolved 1 10 37 2 25 3 35 38 4 45 5 55 6 65 7 75 39 8 85 40 9 95
100

23. Identify the following
Independent Variable
Dependent Variable
Control
Constants
Possible conclusion
Another hypothesis

24. Scientific Law Vs Theory
Observable Fact
True: Always observed
No known exceptions
No explanation
Explanation
Tentative
Can be disproven

25. Development of a Theory
Start with an observation that evokes a question: Broth spoils when I leave it out for a couple of days. Why?
Using logic and previous knowledge, state a possible answer, called a Hypothesis: Tiny organisms floating in the air must fall into the broth and start reproducing.
Perform an experiment or Test: After boiling some broth, I divide it into two containers, one covered and one not covered. I place them on the table for two days and see if one spoils. Only the uncovered broth spoiled.
Then publish your findings in a peer-reviewed journal. Publication: "Only broth that is exposed to the air after two days tended to spoil. The covered specimen did not."
Other scientists read about your experiment and try to duplicate it. Verification: Every scientist who tries your experiment comes up with the same results. So they try other methods to make sure your experiment was measuring what it was supposed to. Again, they get the same results every time.
In time, and if experiments continue to support your hypothesis, it becomes a Theory: Microorganisms from the air cause broth to spoil.
Useful Prediction: If I leave food items open to the air, they will spoil. If I want to keep them from spoiling, I will keep them covered.

26. Chemistry is Central to our Lives
Chemistry is about composition, structure, function, and interaction of matter
Everything has composition, structure, function, and interaction.
All other sciences (biology, physics, geology, etc) have their basis in chemistry

27. Mass Vs Weight Mass Weight Not influenced by gravity
Changes only when amount of matter changes
Kilograms or grams
Affected by gravity
W = mg
g= 9.8 m/s2

28. Your Mass Earth Moon M ass = 60 kg
Gravity = 1/6th the gravity on Earth
Mass = 60 kg
Not affected by gravity

29. Weight Earth Moon m = 60 kg W = mg W = (6o kg)(9.8m/s2)
W = 588 Newtons
m = 60 kg
W = mg
g = 9.8m/s2/6 = m/s2
W = (60 kg)(1.63m/s2)
W = 98 Newtons

30. Environment with No Gravity
Weight only would change
You would weigh less
Amount of Matter is not affected
Mass stays the same

31. Submicroscopic and Macroscopic
Atomic Level
What happens here determines the macroscopic
What we observe
Determined by the submicroscopic (atomic)
Chemist are interested in how the atomic level determines the macroscopic

32. Substance is matter that has a definite composition
Substance is matter that has a definite composition. Also known as a chemical
Element
Compound
One type of atom
Oxygen (O2)
Ozone (O3)
Copper
Two or more types of atoms
Sodium chloride (table salt) NaCl
Ethyl alcohol
H2O

33. Chance Discoveries Discoveries made by accident
Not trying to find an answer
Examples
Velcro
Penicillin
Teflon
Chocolate Chip Cookies
The Microwave Oven
Artificial Sweeteners
Curiosity Drives Discovery