1. Introduction to Chemistry
Chapter 1

2. A Story of Two Substances
Section 1

3. What Is Chemistry?
Chemistry can be defined as the study of matter and the changes it undergoes.
Chemistry is often called the central science.

5. The Ozone Layer

6. Formation of Ozone Destruction of Ozone
See Figure 3 on page 6 for the formation
Destruction of Ozone

8. Substance – Matter that has a definite and uniform composition.

9. Chlorofluorocarbons First synthesized in 1928 by Thomas Midgley Jr.
CFC is a substance that consists of chlorine, fluorine, & carbon.
CFC’s were first considered to be safe.
However by the 1970’s scientists were detecting the presence of CFC’s in the atmosphere.

10. Chemistry & Matter
Section 2

11. Mass – Is a measurement that reflects the amount of matter in an object.
Weight & mass are not the same thing!
Weight – Is a measure of the amount of matter but also of the effect of Earth’s gravitational pull on that matter.

12. Chemistry attempts to explain submicroscopic events that lead to macroscopic observations.
One way to accomplish this is by using a model.
A model is a visual, verbal, or mathematical explanation of experimental data.

13. Scientific Method
Section 3

14. What Is The Scientific Method?
The Scientific Method is a systematic approach used in scientific study.
It is an organized process used by scientists to do research, and it provides a method for scientists to verify the work of others.
This process is essential to science!

15. The Scientific Method
1. State the problem and collect data (make observations)
Observations can be qualitative (like the sky is blue) or quantitative (a measurement or involving a number).
An observation is something that is witnessed and can be recorded.

16. Type of Observations Explained…
Qualitative Data
Descriptions using words
Like color, odor, shape, or some other physical characteristic.
In general, anything that relates to your 5 senses.
Quantitative Data
Descriptions using numbers
Tells how much, how little, how big, how tall, or how fast

17. The Scientific Method Cont.
2. Formulate a hypothesis
A hypothesis is a possible explanation for the observation
A hypothesis is a tentative, testable statement or prediction about what has been observed.

18. The Scientific Method Cont.
3. Perform an experiment
An experiment is something we do to test the hypothesis.
During this process we gather information that allows us to decide whether our hypothesis was correct.
4. Draw Conclusions
Use the information gathered

20. In Experiments…
Experiment – A set of controlled observations that test a hypothesis.
Independent Variable – In an experiment, the variable that the experimenter plans to change.
Dependent Variable – In an experiment, the variable whose value depends on the independent variable.
Control – Many experiments have these to serve as a standard for comparison.

21. Theories
A theory is an interpretation, or a possible explanation of why nature behaves in a particular way.

23. Law
A law tells what happens, and has been proven to be true over time.

24. Scientific Research
Section 4

25. Types of Scientific Investigation
Pure Research – A type of scientific investigation that seeks to gain knowledge for the sake of knowledge itself.
Applied Research – A type of scientific investigation that is undertaken to solve a specific problem.

26. Laboratory Safety

27. Never directly smell or taste anything in the lab – learn to waft if smell is need
Always listen to Teacher’s tips before the lab.
Always READ THE DIRECTIONS FIRST!!!!!
Stick to the lab directions. Unauthorized experiments =trouble.

28. MSDS Labels – “Material Safety Data Sheets” – rank chemicals in certain danger areas on a scale from 1-4.
Flammability – 0 is nonflammable, 4 is very flammable
Remember, in order to burn, oxygen must also be present
Reactivity – 0 means it is very inert (doesn’t react with much), 4 is very reactive
Health – 0 is safe (NaCl is a 1), 4 is very dangerous
Remember, you should never eat things in the lab

29. MSDS Sheet Example