1. Chemistry and Scientific Methods
Fall 2009
Chemistry and Scientific Methods

2. What is Chemistry?
The branch of science that deals with the properties of substances and the reactions that transform them into other substances.
AKA – the study of matter and the changes it undergoes
Chemistry is a central science.
Chemistry uses the scientific method to advance its knowledge.

3. What is Matter? Matter is anything that has mass and takes up space.
Mass is a measurement that reflects the amount of matter in a sample of a substance.
Weight is a measure not only of the amount of matter, but also the effect of Earth’s gravitational pull on that matter.
Volume is a measurement of the amount of space taken up by the sample of matter.

4. Chemistry Chemistry As a Central Science Atmospheric Sciences Physics
Oceanography
Medicine
Economics
Governments
Chemistry
People
Geology
Biology
Politics
Astronomy
Anthropology

5. Branches of Chemistry – Table 1-1 p.9
Area of Emphasis
Examples
Organic Chemistry
Most carbon-containing chemicals
Pharmaceuticals, plastics
Inorganic Chemistry
In general, matter that does not contain carbon
Minerals, metals and nonmetals, semi-conductors
Physical Chemistry
The behavior and changes of matter and the related energy changes
Reaction rates, reaction mechanisms
Analytical Chemistry
Components and composition of substances
Food nutrients, quality control
Biochemistry
Matter and processes of living organisms
Metabolism, fermentation

6. The Scientific Method
It is an orderly and systematic approach to answering questions about the worls.
Information or data is gathered by careful observation of the phenomenon being studied.
On the basis of that information a preliminary generalization or hypothesis is formed.
A series of experiments is devised to test the predictive power of the hypothesis.

7. The Scientific Method (cont.)
On the basis of the experimental tests, the hypothesis may be
(a) Accepted as scientific theory.
(b) Modified so that all results are adequately explained.
(c) Discarded.

8. Components of the Scientific Method
Making Observations
Formulating Hypothesis
Extracting Predictions From the Hypothesis
Performing Experiments
Drawing Conclusions
Communicating Results

9. Experimental Variables
A variable is any factor in the experiment that can change.
Independent variable – the variable that the researcher plans to change
Dependent variable – the variable that you are measuring to see if it was effected by the change in the independent variable
Constants – factors that you keep the same among all trials so that they do not effect the results

10. What is a control? A control is a standard for comparison.
It helps the researcher to know what would happen under “normal” conditions.

11. Definitions
Law – a summary of observed behaviors. (It describes but does not explain.)
Ex. Law of Gravitation or Newton’s 3 Laws of Motion
Hypothesis – a possible explanation of an observation or set of observations.
Theory – A set of tested hypothesis that gives an overall explanation of some natural phenomenon or phenomena.
Ex. Atomic Theory or Einstein’s Theory of Relativity

12. Remember: The #1 job of a scientist is to rule out hypotheses.
"The great tragedy of Science - the slaying of a beautiful hypothesis by an ugly fact."
- T.H. Huxley

13. Scientific Research
Pure research seeks to gain knowledge for the sake of knowledge. (Just curious about what would happen if…)
Applied research is undertaken to solve a specific problem. (How can we prevent to hole in the ozone from getting bigger?)
Technology is the practical use of scientific knowledge. (cell phones, electric cars, etc.)

14. Textbook Assignment
Review the Chapter Summary for Sections on p.21.
Look a the vocabulary words on p.22. Add any terms and definitions not covered in your notes to the bottom of your notes.
On a separate sheet of loose-leaf paper to turn in write the questions and answers for p.22 (27-34).