Intro to Chemistry & the Scientific Method

Chemistry- study of the composition of matter and the changes that matter undergoes

Organic Physical Inorganic Analytical Biochemistry

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

1) Problem - “What’s wrong?”

2) Hypothesis - “Educated Guess” predict what will happen based on prior knowledge

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

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

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

when graphing… Keep in mind: D R Y M I X dependent independent

4) Observations & Data collection

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

Observation vs. Inference Observation – the act of gathering information. You actually see it! Inference – an opinion based on the observations.

observation inference observation inference inference inference observation inference

Quantitative vs. Qualitative - Qualitative – describes physical characteristics Color, Odor, Shape, Sound, Taste, Texture, Etc… Quantitative – numerical information How Much? How Tall? How Fast? How Many? Etc…

Scientific Law vs. Theory Scientific Law – summarizing statement of many experiments Has been proven, usually stated in a mathematical formula - Scientific Theory – thoroughly tested explanation of why experiments give certain results Can NOT be proven, helps predict natural systems

EX: Atomic Theory Charles Law