1. The Scientific Method
Chemistry CP

3. The Scientific Method
The SCIENTIFIC METHOD is a logical, systematic approach to the solution of a scientific problem.

4. Steps of the Scientific Method
1. Make OBSERVATIONS
2. Form a HYPOTHESIS
3. Conduct an EXPERIMENT
Record and COLLECT DATA
Analyze your DATA and RESULTS
4. State your CONCLUSIONS

5. What makes the scientific method possible?
At the root: humans are curious
Experimental science is actually the search for cause and effect relationships in nature.
If…... then…….

6. OBSERVATIONS YOU… Notice something and wonder why it happens
See something and wonder what causes it
Want to know how or why something works
Ask questions about what you have observed
Want to investigate

7. OBSERVATIONS Qualitative observations: Quantitative observations:
Using your five senses – see, feel, sound, taste or smell
Color, odor, shapes are all qualitative observations.
Quantitative observations:
Numeric data
Temperature, mass, volume are all quantitative observations.

8. What’s wrong with the flashlight?
OBSERVATIONS
Suppose you try to turn on a flashlight and it does not light.
Your observation leads to a question:
What’s wrong with the flashlight?

9. HYPOTHESIS
A hypothesis is an educated guess - a proposed explanation for an observation
You guess or hypothesize that the flashlight needs new batteries.

10. HYPOTHESIS There are no right or wrong hypotheses
Usually the more reasonable hypothesis becomes the one that is tested and verified
A “correct” hypothesis can become a theory with support from further testing

11. EXPERIMENTS
Test the hypothesis with an experiment
An experiment is set of controlled observations.
You can test your hypothesis by putting new batteries in the flashlight. If the flashlight lights, your hypothesis was true.

12. EXPERIMENTAL PROCEDURES
Select only one thing to change in each experiment – the variable
Independent variable: the one you will change
Dependent variable: the one you will measure
Change something that will help you answer your question(s)
Test the effect of temperature on salt dissolving.
Change/vary the temperature
Measure how fast salt dissolves

13. EXPERIMENTAL PROCEDURES
The procedure must tell how you will change this one thing and how you will measure the amount of change
Each experiment should have a “control” for comparison so that you can see what the change actually did

14. EXPERIMENTS (Cont.)
Experiments are done many times to guarantee that what you observe is reproducible
Reduce the chance that you have made an experimental error or observed a random effect

15. DATA COLLECTION AND ANALYSIS
Record your observations during the experiment. Quantitative Observations = Experimental Data
Summarize what happened based on the analysis of the data or results:
table or graphs
a statement of what occurred

16. CONCLUSIONS
Based on the results of your data analysis, conclusions can be drawn
These conclusions help us confirm or deny the original hypothesis
Sometimes you will need to revise your hypothesis if the original is “incorrect”

17. THEORIES
Once a hypothesis is well-tested and reproducible, it may become a theory
A theory is a well-tested explanation of a set of observations
Sometimes a theory will be revised to explain new observations

18. SCIENTIFIC LAWS
A scientific law is a statement of fact describing a set of observations.
It is generally accepted to be true and universal.
Examples: Law of Gravity, Law of Conservation of Mass, Law of Conservation of Energy