Intro unit: Nature of ScienceIntro unit: Nature of Science

Science is organized Science is organized commoncommon sensesense

HypothesisHypothesis: An educated guess, : An educated guess, based upon prior based upon prior knowledge/experiences knowledge/experiences

InferenceInference: :

logical explanation logical explanation

of an event based of an event based

on observable on observable

characteristics characteristics

(even without all(even without all

of the information)of the information)

ControlledControlled Variables – variables kept constant Variables – variables kept constant so as to not affect resultsso as to not affect resultsex: same plants, same soil, same temp. same light, etc.ex: same plants, same soil, same temp. same light, etc.

IndependentIndependent (Manipulated) Variable – (Manipulated) Variable – variable changed on purpose (it’s the factor variable changed on purpose (it’s the factor being tested) being tested)

ex. plant 1= 100ml Hex. plant 1= 100ml H220, plant 2=50ml H0, plant 2=50ml H22O, plant 3=10ml O, plant 3=10ml HH22OO

DependentDependent (Responding) Variable – the (Responding) Variable – the results. It’s what happens as a result of the results. It’s what happens as a result of the manipulated variablemanipulated variable

ex. plant 1 grew 4 inches, plant 2 grew 2 inches, plant 3 diedex. plant 1 grew 4 inches, plant 2 grew 2 inches, plant 3 died

[You can never have more than 1 independent [You can never have more than 1 independent variable, or you would not know which variable variable, or you would not know which variable caused the results.]caused the results.]

DataData:: Information gathered through Information gathered through observation. observation.

QualitativeQualitative data uses the senses data uses the senses

ex. table is smooth, black, hard, rectangle, etc.ex. table is smooth, black, hard, rectangle, etc.

QQuantitativeuantitative data uses data uses measurementsmeasurements

ex. table top is 150 cm long and 30 cm wideex. table top is 150 cm long and 30 cm wide

Steps in the Problem Solving Method:Steps in the Problem Solving Method: State the Problem: State the Problem:

{what are you trying to find out?}{what are you trying to find out?} State the HypothesisState the Hypothesis

{what do you think will happen? Why?}{what do you think will happen? Why?}

Test the HypothesisTest the Hypothesis{list materials & directions to use those materials.}{list materials & directions to use those materials.}

Record & Analyze DataRecord & Analyze Data{quantitative, or quantitative data; data tables, or {quantitative, or quantitative data; data tables, or

graphs}graphs} Draw ConclusionsDraw Conclusions

{multiple sentences: What did you learn, confirm, etc. {multiple sentences: What did you learn, confirm, etc. Identify factors affecting the results, major concepts,Identify factors affecting the results, major concepts,

questions the experiment generated, etc.}questions the experiment generated, etc.}

Graphs & Tables – used to Graphs & Tables – used to collectcollect and and analyzeanalyze data data (a picture of the results). (a picture of the results).

Independent variable goes on the X-axis. Independent variable goes on the X-axis. Dependent variable goes on the Y-axis.Dependent variable goes on the Y-axis.

Always give a graph a descriptive title, and completely and Always give a graph a descriptive title, and completely and accurately label the X & Y axis.accurately label the X & Y axis.

Line Line graph shows graph shows

change over time.change over time.BarBar graph compares graph compares

amountsamounts

Circle Circle graph (pie chart) shows the parts graph (pie chart) shows the parts compared to the whole. compared to the whole.

TheoryTheory – a well tested explanation that explains – a well tested explanation that explains a phenomena, based on many observations a phenomena, based on many observations over a number of years over a number of years (ex: Big Bang Theory)(ex: Big Bang Theory)

Scientific Scientific LawLaw – a tested and proven fact of – a tested and proven fact of nature. It happens that way every time. nature. It happens that way every time. (Ex: (Ex: Law of Gravity)Law of Gravity)

Scientific Scientific ModelModel –a representation used to –a representation used to explain a concept that may be to small, large, explain a concept that may be to small, large, far way, dangerous, etc. to be studied far way, dangerous, etc. to be studied otherwise. otherwise.

(3-D model, picture, diagram, equation, etc.)(3-D model, picture, diagram, equation, etc.)

Scientific Notation - a type of Scientific Notation - a type of shorthand in which a number is shorthand in which a number is expressed as a value between expressed as a value between 11 and and 1010 multiplied by a power of 10. multiplied by a power of 10.

Examples: Examples:

4 x 104 x 102121 is is 4,000,000,000,000,000,000,0004,000,000,000,000,000,000,000

3.141 x 103.141 x 101818 is is 3,141,000,000,000,000,0003,141,000,000,000,000,000

Primary Scientific MeasurementsPrimary Scientific Measurements Length Length or or DistanceDistance: Meter Stick, meters; : Meter Stick, meters;

m, cm, mmm, cm, mm MassMass: Balance Scale, grams; g or kg: Balance Scale, grams; g or kg VolumeVolume: Beaker or Graduated Cylinder; : Beaker or Graduated Cylinder;

liters; L or mLliters; L or mL TemperatureTemperature: Thermometer, degrees : Thermometer, degrees

celsius; celsius; ºCºC TimeTime: Clock, Calendar; min., s, hr, day, etc.: Clock, Calendar; min., s, hr, day, etc.

Sometimes 2 types of measurement Sometimes 2 types of measurement

are combined. are combined.

Examples:Examples:

Density: mass/volume 10 g/2 ml = 5 g/mlDensity: mass/volume 10 g/2 ml = 5 g/ml

Speed: distance/time 10 m/5 s = 2 m/sSpeed: distance/time 10 m/5 s = 2 m/s

Metric SystemMetric System

Scientific measurements are made Scientific measurements are made in metrics for the following reasons:in metrics for the following reasons:

1.1. Recognized world wideRecognized world wide

2.2. More accurateMore accurate

3.3. Easier because it’s based on 10 Easier because it’s based on 10 (just moved decimals to convert)(just moved decimals to convert)

Metric Prefixes Metric Prefixes milli- milli- mm 0.0010.001 centi-centi- cc 0.010.01 deci- ddeci- d 0.10.1 Deka- dk 10Deka- dk 10 Hecto- h 100Hecto- h 100 Kilo- k 1000Kilo- k 1000 To convert from a smaller to a larger unit, To convert from a smaller to a larger unit,

move the decimal to the left equal to the move the decimal to the left equal to the number of zeros.number of zeros.

To convert from a larger to a smaller unit, To convert from a larger to a smaller unit, move the decimal to the right equal to the move the decimal to the right equal to the number of zeros.number of zeros.