1. Section 2: Scientific Methods
Scientists use scientific methods to systematically pose and test solutions to questions and assess the results of the tests. K
What I Know W
What I Want to Find Out L
What I Learned

2. Chemistry is the branch of science that studies matter and the changes that it undergoes.
Science is the use of evidence to construct testable explanations and predictions of natural phenomena as well as the knowledge gained through this process.
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Scientific Methods

3. Matter is anything that has mass and takes up space.
Mass reflects the amount of matter in a substance.
Weight is dependent on gravity while mass is not. They both are an indication of how much matter is in a substance.
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Scientific Methods

4. Much of matter and its behavior is macroscopic.
It can be observed without a microscope.
The structure, composition and behavior of all matter can be described on the microscopic (atomic) level.
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Scientific Methods

5. Science can only answer questions that are testable by experiment.
A model is a physical, conceptual or mathematical explanation of experimental data.
Science can only answer questions that are testable by experiment.
Scientific inquiry is the planned and deliberate investigation of the natural world.
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Scientific Methods

6. Essential Questions What are the common steps of scientific methods?
What are the variables and the controls in an experiment?
What is the difference between a scientific theory and a scientific law?
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Scientific Methods

7. Vocabulary Review New New systematic approach experiment
independent variable
dependent variable
control
conclusion
scientific theory
scientific law
New
scientific method
qualitative data
quantitative data
hypothesis
Scientific Methods
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8. A Systematic Approach
The scientific method is a systematic approach used in scientific study, whether it is chemistry, physics, biology, or another science. It is an organized process used by scientists to do research, and provides methods for scientists to verify the work of others. The steps in a scientific method are repeated until a hypothesis is supported or discarded.
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Scientific Methods

9. An observation is the act of gathering information.
A Systematic Approach
An observation is the act of gathering information.
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.
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Scientific Methods

10. Qualitative vs. Quantitative

11. Scientific Method 5 Steps: 1. Problem 2. Hypothesis 3. Experiment
4. Observations & Data
5. Conclusion 11

12. 1) Problem -
“What’s wrong?” 12

13. 2) Hypothesis - “Educated Guess” predict what will happen
Based on prior knowledge 13

14. 3) Experiment - Test your hypothesis
a) Control Group – stays the same, used for comparison
b) Variable Group – what you
manipulate that changes 14

15. 1. Independent Variable – what the experimenter (I) changes.
2. Dependent Variable – what is observed/measured.
The dependent variable depends on the independent variable
The independent variable is what I change!!! 15

16. If you were trying to determine if temperature affects bacterial growth, you would expose different petri dishes of the same bacteria to different temperatures.
Temperature is your independent variable.
Bacteria growth is your dependent variable.

17. 3. Control Variables – all other variables that are kept constant.
Remember, a good experiment only has two variables that change (independent and dependent). All the rest of the variables must be the same. 17

18. During clinical drug trials, physicians will use a double-blind study
During clinical drug trials, physicians will use a double-blind study. They use two statistically identical groups of patients. One will receive the drug and one will receive a placebo. Neither patient or physician will know which group receives the drug.
The group receiving the placebo is the control group.

19. when graphing… 19

20. 4) Observations
&
Data collection 20

21. 5) Conclusion -
- Based on observations
Might support hypothesis! 21

22. Theory and Scientific Law
A scientific theory is an explanation that has been repeatedly supported by many experiments.
A theory states a broad principle of nature that has been supported over time by repeated testing.
Theories are successful if they can be used to make predictions that are true.
A scientific law is a relationship in nature that is supported by many experiments, and no exceptions to these relationships are found.
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Scientific Methods

23. Applied research is research undertaken to solve a specific problem.
Scientific Research
Pure research is research to gain knowledge for the sake of knowledge itself.
Applied research is research undertaken to solve a specific problem.
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Scientific Methods

24. Review Essential Questions scientific method qualitative data
What are the common steps of scientific methods?
What are the variables and the controls in an experiment?
What is the difference between a scientific theory and a scientific law?
Vocabulary
scientific method
qualitative data
quantitative data
hypothesis
experiment
independent variable
dependent variable
control
conclusion
scientific theory
scientific law
Copyright © McGraw-Hill Education
Scientific Methods