Chapter 1 The Nature of Science

I. What is Science? A. Science comes from the Latin word scientia, which means “knowledge” 1. Science- process that uses observation and investigation to gain knowledge about events in nature. B. Three branches of Science 1. Life Science Deals with living things Deals with living things

2. Earth Science Investigates earth and space Investigates earth and space 3. Physical Science Deals with matter and energy Deals with matter and energy C. How do scientists learn about the natural world? 1.Performing investigations Observation Observation Experiments Experiments models models

II. Scientific Method- Organized set of investigation procedures A. Six step method 1.State the problem 2.Gather information 3.Form a hypothesis 4.Test the hypothesis 5.Analyze data 6.Draw conclusions Support/Doesn’t support Hypothesis Support/Doesn’t support Hypothesis If hypothesis is supported, repeat steps 4-6 several times If hypothesis is supported, repeat steps 4-6 several times If hypothesis is not supported, go back to step 3 and form a new hypothesis If hypothesis is not supported, go back to step 3 and form a new hypothesis

1. Stating the problem The problem is a question of “WHY?” or “WHAT?” The problem is a question of “WHY?” or “WHAT?” Example- What materials can be used to create a space shuttle that will with stand the harsh conditions of space?Example- What materials can be used to create a space shuttle that will with stand the harsh conditions of space?

2. Researching and Gathering Information Gather information that will help solve the problem Gather information that will help solve the problem Example- melting points of different materials that could be used to build a space shuttleExample- melting points of different materials that could be used to build a space shuttle

3. Form A Hypothesis Hypothesis- A possible explanation for a problem using what you know and what you observe Hypothesis- A possible explanation for a problem using what you know and what you observe In the form of an IF/THEN statementIn the form of an IF/THEN statement Example- If a ceramic material is used then the space shuttle will be able to withstand the high temperatures.Example- If a ceramic material is used then the space shuttle will be able to withstand the high temperatures.

4. Test a Hypothesis Can be done by performing an experiment, making observations or building a model Can be done by performing an experiment, making observations or building a model An experiment uses two variables, a dependant and an independent variableAn experiment uses two variables, a dependant and an independent variable Variable- quantity that can have more than a single value Variable- quantity that can have more than a single value Dependant variable- value changes according to changes in other variables Dependant variable- value changes according to changes in other variables Independent Variable- Is independent of other variables Independent Variable- Is independent of other variables

Example 1- what factors might cause a plant to grow? Example 1- what factors might cause a plant to grow? Independent variable- growthIndependent variable- growth Dependent variable- water, sunlight, soilDependent variable- water, sunlight, soil Example 2- The higher the temperature of water, the faster an egg will boil Example 2- The higher the temperature of water, the faster an egg will boil Independent variable- water tempIndependent variable- water temp Dependent variable- speed/ timeDependent variable- speed/ time

Example 3- An investigation was done with an electromagnetic system made from a battery and wired wrapped around a nail. Different sizes of nails were used. The number of paperclips the electromagnet could pick up was measured. Example 3- An investigation was done with an electromagnetic system made from a battery and wired wrapped around a nail. Different sizes of nails were used. The number of paperclips the electromagnet could pick up was measured. Independent variable- nail size Independent variable- nail size Dependent variable- how many paperclips were picked up Dependent variable- how many paperclips were picked up

Experiments also have CONSTANTS and CONTROLS Experiments also have CONSTANTS and CONTROLS Constant- A factor that does not change when other variables doConstant- A factor that does not change when other variables do Controls- Standard by which the test results can be compared.Controls- Standard by which the test results can be compared. Example- Have 4 plants with the same soil and amount of fertilizer. Three of the plants get different types of fertilizer and the fourth gets none. Example- Have 4 plants with the same soil and amount of fertilizer. Three of the plants get different types of fertilizer and the fourth gets none. Constant- soil and sunlightConstant- soil and sunlight Control- plant that does not receive fertilizerControl- plant that does not receive fertilizer

5. Analyzing Data This is done by recording observations making charts and graphs This is done by recording observations making charts and graphs

6. Drawing Conclusions Based on data analysis, is your hypothesis supported or not? Based on data analysis, is your hypothesis supported or not? You must be objectiveYou must be objective Bias- When the scientists expectations changes how the results are viewed Bias- When the scientists expectations changes how the results are viewed

Scientific Theories and Laws Theory- explanation of things or events based on knowledge gained from many observations and investigations Theory- explanation of things or events based on knowledge gained from many observations and investigations Scientific Law- A statements about what happens in nature and seems to be true all the time. Scientific Law- A statements about what happens in nature and seems to be true all the time.

Standards of Measurement Chapter 1 Section 2

Units and Standards Standard- an exact quantity that people agree to use for comparison Standard- an exact quantity that people agree to use for comparison Examples- ???Examples- ??? International System of Units International System of Units SI standard- universally excepted units of measurement used by scientistsSI standard- universally excepted units of measurement used by scientists Measured in the Power of 10Measured in the Power of 10

Different Measurements Mass- amount of matter in an object Mass- amount of matter in an object Measured in gramsMeasured in grams Volume- The amount of space occupied by an object Volume- The amount of space occupied by an object Measured in liters or gramsMeasured in liters or grams Volume = length X width X heightVolume = length X width X height Length- distance between two points Length- distance between two points Measured in metersMeasured in meters

SI Units Quantity Measured Unit and SymbolExamples LengthMeter (m) Massgram (g) TimeSecond (s) VolumeLiter (L) TemperatureCelsius ( C )

SI prefixes UnitSymbolValue MegaM1,000,000 Kilok1,000 Hectoh100 Decada10 Basic Unit (gram, meter, liter, etc.) Decid0.1 Centic0.01 Millim0.001 Micro m L R

Conversion examples!

Communicating with Graphs Chapter 1 Section 3

Graphs Graph- visual display of information or data Graph- visual display of information or data X-axis- horizontal axisX-axis- horizontal axis Independent variable Independent variable Y-axis- vertical axisY-axis- vertical axis Dependant variable Dependant variable Three types of graphsThree types of graphs 1. Line 2. Bar 3. pie Y-axis dep. variable X-axis ind. variable

Line Graphs Often used to show change over time Often used to show change over time

Bar Graphs Used for comparing information collected by counting Used for comparing information collected by counting

Pie Charts Used to show how a fixed quantity is broken down into parts Used to show how a fixed quantity is broken down into parts Usually represented in percentsUsually represented in percents

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