Introduction to Chemistry - Unit 1

Intro to Chemistry & The Scientific Method

Chemistry

The study of how one type of stuff is transformed into another type of stuff

Matter

The “stuff” that is anything you can taste, touch, or smell

Transformations

Done through the making and breaking of chemical bonds

5 Main Branches of Chemistry

1. Organic Chemistry

2. Inorganic Chemistry

3. Physical Chemistry

4. Analytical Chemistry

5. Biochemistry

Organic Chemistry

Study of stuff that is carbon based, but also containing hydrogen, oxygen, and nitrogen

Inorganic Chemistry

Study of chemical compounds that are not organic, often involving metals

Physical Chemistry

Study of how energy interacts with stuff

Analytical Chemistry

Identifying & measuring matter using sophisticated equipment

Biochemistry

The chemistry of living things

The Scientific Method

Problem solving in a scientific way

• Systemic approach used in scientific study

• Provides a method for scientists to verify the work of others

Steps of the Scientific Method

1. Purpose

2. Form Hypothesis

3. Experiment

4. Analyze Results

5. Draw Conclusions

Purpose

The problem that needs solving or reason for the investigation. What you are trying to figure out

Hypothesis

The educated guess about what will solve the problem. Should be a prediction that can be tested

Experiment

Study your set up to manipulate an independent variable to change the dependent variable of the experiment

Variable

A quantity or condition that can have more than one variable

Results

The data gathered or what happened in the experiment

• Include measurements and/or observations

• Very careful record keeping of multiple trials is important for valid, reliable results

• Use charts or tables to organize data

Quantitative Data

Numerical Data

Qualitative Data

Descriptive Data

Conclusion

What does it all mean? Did the problem get solved?

Should include discussion of how the experiment could be improved or done differently to improve it

Independent Variable

Thing or condition you’re testing. The one variable you will change

Dependent Variable

What you measure to compare the results of your test. The data you chart or graph

Constants

Variables unallowed to change. What you keep the same each test/trial

Controlled Variable (control)

What you will compare your results to when analyzing results

• Usually the trial/case where the independent variable is 0 or not included. Sometimes it’s the default or regular state/condition

Process of Understanding in Science

• If a scientist observes something interesting or cool, they may come up with a hypothesis to explain it

• If that hypothesis is shown to be true through experimentation, then a model is proposed to explain the phenomenon

• That model is then tested repeatedly to see if it actually works. If not, then it’s adjusted

• When a model gets confirmed over and over again by experiment, it becomes a theory

Theory

A well-developed, widely-accepted, continually tested explanation of how something happens or works. They explain how & why things happen

Laws

Simple statements that tell you what happens

Two Types of Scientific Research

Pure research & applied research

Pure Research

Research that is done for fun or because it’s interesting, not necessarily for any defined purpose

Applied Research

Research done when there’s a problem to solve and scientists look to find solutions. Not really looking to discover something new