CHAPTER 1 NOTES
Science – the process of observing and studying and experimenting
Scientific Method – a step by step approach used for problem solving
Scientific Method
1. determine problem
2. make hypothesis ( educ. guess)
3. test hypothesis
4. analyze results
5. conclusion
Hypothesis – an educated guess
Theory – a hypothesis which has been repeatedly tested. Can be wrong
Law – rule of nature. Describes behavior Gravity
Experiments
Scientists use an experiment to search for cause and effect relationships in nature. Testing the Hypothesis
Variables – part of the experiment that can exist in differing amounts or types.
Independent Variable – the variable that is changed by the scientist. A good experiment has only one independent variable
Dependent Variable - The part of the experiment that changes when the independent variable changes. Dependent Variables are changes in the experiment that occur due to changes in the independent variable.
Controlled Variable – quantities that are to remain constant. A control variable is anything else that could influence the dependent variable
Question / Independent Variable(What I change) / Dependent Variables
(What I observe) / Controlled Variables
(What I keep the same)
Does heating a cup of water allow it to dissolve more sugar? / Temperature of the water measured in degrees Centigrade / Amount of sugar that dissolves completely measured in grams / · Stirring
· Type of sugar
"More stirring might also increase the amount of sugar that dissolves and different sugars might dissolve in different amounts, so to insure a fair test I want to keep these variables the same for each cup of water."
Types of measurements
Distance – measures the space between two points
Mass – measure of the amount of matter in an object. Does not change based on location
Weight - measures the amount of gravitational pull on an object. Changes based on location
Volume – measures the amount of space an object takes up or occupies
Temperature – measures the rate of molecular movement.
Density – the amount of matter in a given volume. D = M/V
Describes how closely packed the molecules are to each other
Metric System
3 Base Units
Meter – distance - yard
Liter – volume – quart (gallon)
Gram – mass – ounce (paper clip)
Metric prefixes
milli 1/1000 .001
centi 1/100 .01
kilo 1000 1000.
Models
Model – a representation or description of an object, system, process or concept.
Physical Model – a three dimensional object that represent an actual object, system, process or concept. globe
Conceptual Model – Verbal or graphical models that represent how a system works or is organized. Flow chart
Mathematical Model – equations that represent the way a system or process works.