The Nature of Science

Observing You have two beakers, each containing a clear liquid and an ice cube. What do you observe?

Fact & Opinion Fact –Is true for everyone Opinion –Personal belief that is not founded on proof Inference –Conclusion based on observation

Density A measure of how heavy a solid, liquid, or gas is for its size Density is expressed in terms of mass per unit volume

Observing Density

Graphing Density Comparison of the density of different liquids Red Blue Green Type of liquid Density 9n g/c 3 Descriptive title Specific I / M V Label General I / M V Label D / R V Label UNITS!!! Label Scale

Writing Experimental Questions Effect & Affect –What is the effect (of the independent / manipulated variable) on the (dependent / responding variable)? –How does (the independent / manipulated variable ) affect the (dependent / responding variable)?

Developing Hypotheses If, Then If the (independent / manipulated variable) changes, Then the dependent / responding variable) will change. [How will it change? Increase? Decrease?]

Designing Experiments Very detailed –Step-by-step Independent / manipulated variables identified Dependent / responding variables identified Units of measurement identified Repeated trials

Making Data Tables I / M V Label Repeated Trials Reduced Data Density of Liquids in g/c 3 Descriptive title with UNITS Room for Data

Drawing Conclusions Restate original question & hypothesis Answer original question Accept or reject hypothesis based on data –Describe data as evidence Describe relationships Identify sources of error

Density Challenge! Can you make your beaker look like this?

Hint Think about density first Think about color last