1. What is Chemistry? What is Matter? What is Mass?
the study of matter and the changes that it undergoes.
What is Matter?
anything that has mass and takes up space
What is Mass?
a measurement of the amount of matter in an object

2. Mass verses Weight They are related, but what’s the difference?
Mass is universal, weight depends on gravity
Weight = mass times the gravitational pull

3. Branches of Chemistry Organic Inorganic Analytical Physical
Biochemical

4. Organic Area of Emphasis Most carbon-containing chemicals Examples:
Pharmaceuticals
Plastics

5. Inorganic Area of Emphasis
In general, matter that does not contain carbon
Examples:
Minerals
Metals and nonmetals
Semi-conductors

6. Analytical Area of Emphasis Components and composition of substances
Examples:
Food Nutrients
Quality Control

7. Physical Area of Emphasis
The behavior and changes of matter and the related energy changes
Examples:
Reaction Rates
Reaction Mechanisms

8. Biochemical Area of Emphasis Matter and processes of living organisms
Examples:
Metabolism
Fermentation

9. Next, the Scientific Method

10. Why do we have the scientific method?
Gives us logical steps to follow to assist us in answering a question.

11. What are the “steps”? Develop a question Conduct background research
Form a hypothesis
Test with an experiment
Make observations and collect data
Analyze the results
Draw conclusions
Report results and test again

12. Step 1: Ask a Question
Scientists ask questions based on observations from their surroundings

13. Step 2: Form a Hypothesis
Take an educated guess about what you think the answer is to your question

14. Step 2: Form a Hypothesis
Hypothesis: an educated guess or prediction; an “if, then” statement
If ____independent variable______
then__dependent variable_______

15. Example: Independent Variable: I feed my cat a lot of food
she will get fat
If ___________________________
then _________________________

16. Try to use INCREASE and DECREASE in your hypothesis!
Remember
Try to use INCREASE and DECREASE in your hypothesis!
Ex. IF I increase the amount of food I give my cat, THEN she will increase her weight

17. Step 3: Test your hypothesis
Set up an experiment to test your question

18. Types of Variables There are 2 main types of variables:
Independent Variable: The variable that is changed by the scientist; the ‘I control’ variable
Dependent Variable: The variable that might change because of what the scientist changes – what is being measured

19. Remember! Your hypothesis can TELL you what your variables are!
Ex. If I drink Mountain Dew before bed, then I will not sleep very much.
IV: Drinking Mountain Dew
DV: the amount of sleep

20. Use this hypothesis to identify the variables:
Practice
Use this hypothesis to identify the variables:
If I leave all the lights on all day,
then my electric bill will be expensive
IV: ______________________
DV: ______________________

21. If I brush my cat more, then there will be less fur on my furniture
IV: ______________________
DV: ______________________

22. Now read the following experiment and identify the independent and dependent variables
Elizabeth wanted to test if temperature affected how fast milk goes bad and curdles. She left milk in a room temperature closet, a fridge, and a oven that was turned on low heat. She then measured how rotten the milk was after 10 days.
IV: ____________________________________
DV: ____________________________________

23. Step 4: Analyze Your Results
Look at your results and decide what they tell you about your question

24. Step 5: Form a Conclusion
Decide what the answer to your question is and ask:
Was my hypothesis right or wrong?
Do I need to do the experiment again to find out more?

25. Parts of an experiment

26. Independent Variable Part of the experiment that the scientist changes
What is being tested
There is only one independent variable at a time.
What I change

27. Dependent Variable
Part of the experiment that changes because of the independent variable

28. Part of the experiment that does not receive the independent variable
Control
Part of the experiment that does not receive the independent variable

29. Constants
Part of the experiment that remain the same for every part of the experiment

30. Types of Data Quantitative Data that is numerical in nature
Qualitative
Data that is descriptive in nature

31. An example experiment
A person wants to test whether music can help make plants grow. The person plants several seeds from the same batch into identical flower pots with identical potting soil, watering schedule and light supply. One flower pot is isolated from the sound supply, while the other pots are subjected to various types of music. After 1 month, the “healthiness” of each plant is measured.