Chapter 1Chapter 1Science SkillsScience Skills

Mr. BruderMr. Bruder

What is Science?What is Science?

• Science is what scientists doScience is what scientists do

• Science is trying to explain the world Science is trying to explain the world around usaround us

• Science is a way of thinkingScience is a way of thinking

• ““Science is a system of knowledge Science is a system of knowledge based on facts or principlesbased on facts or principles

• Book talks about “social science”Book talks about “social science”

• We prefer social We prefer social studiesstudies

BiologicalScience

EarthScience

PhysicalScience

Branches of ScienceBranches of ScienceScience

BiologicalScience

EarthScience

PhysicalScience

Branches of ScienceBranches of Science

Science of living things

Science

Zoology

Botany

Ecology

BiologicalScience

EarthScience

PhysicalScience

Branches of ScienceBranches of Science

Science of matter and energy

Science

Chemistry

Physics

Astronomy

Meteorology

BiologicalScience

EarthScience

PhysicalScience

Branches of ScienceBranches of Science

The systems of the earth

Science

Geology

Branches of ScienceBranches of Science

• There are many more branches to There are many more branches to biological and earth sciencesbiological and earth sciences

• The three categories overlapThe three categories overlap

• BiochemistryBiochemistry

• AstrobiologyAstrobiology

• GeophysicsGeophysics

What is Chemistry?What is Chemistry?

• The study of matter, its composition, The study of matter, its composition, properties, and the changes it properties, and the changes it undergoesundergoes

• Applied Chemistry is the using of Applied Chemistry is the using of chemistry to attain certain goals, in chemistry to attain certain goals, in fields like medicine, agriculture, and fields like medicine, agriculture, and manufacturingmanufacturing

• Pure Chemistry gathers knowledge Pure Chemistry gathers knowledge for knowledge sakefor knowledge sake

Which Comes First?Which Comes First?

• Pure ChemistryPure Chemistryusually comes first, usually comes first, applied laterapplied later

Called Called technologytechnology

Or engineeringOr engineering

Pure chemistry can Pure chemistry can explain behavior that explain behavior that has been used has been used without knowing whywithout knowing why

Steel swordsSteel swords

Applied ChemistryApplied Chemistry

Can’t be good or Can’t be good or badbad

Can be good or bad Can be good or bad depending on usedepending on use

Chemistry isChemistry is

• A natural scienceA natural science

• A language with its own vocabularyA language with its own vocabulary

• A way of thinkingA way of thinking

Branches of ChemistryBranches of Chemistry• Analytical ChemistryAnalytical Chemistry -studies -studies

composition of substances.composition of substances.• Organic ChemistryOrganic Chemistry -compounds -compounds

containing carboncontaining carbon• Inorganic ChemistryInorganic Chemistry -substances without -substances without

carboncarbon• BiochemistryBiochemistry- Chemistry of living things- Chemistry of living things• Physical ChemistryPhysical Chemistry studies behavior of studies behavior of

substancessubstances– rates and mechanisms of reactionsrates and mechanisms of reactions– energy transfersenergy transfers

Science From CuriosityScience From Curiosity

• Science begins with curiosity and Science begins with curiosity and often ends with discovery.often ends with discovery.

• How or Why is this possible?How or Why is this possible?

• Curiosity provides questions but is Curiosity provides questions but is seldom enough to achieve scientific seldom enough to achieve scientific results.results.

• Then how do we achieve these Then how do we achieve these results?results?

ObservationsObservations

• Qualitative – describe with wordsQualitative – describe with words– Hot , red, largeHot , red, large

• Quantitative – describe with numbersQuantitative – describe with numbers– 100° , 10 meters, 3.46 grams100° , 10 meters, 3.46 grams

• Scientists prefer quantitativeScientists prefer quantitative

• Easy to agree uponEasy to agree upon

• No personal bias No personal bias

ModelsModels

• A representation of some object or A representation of some object or eventevent

• Made to better understand itMade to better understand it• Often used if real thing is too big, Often used if real thing is too big,

small or complex.small or complex.• Come in a variety of formsCome in a variety of forms

– Physical modelsPhysical models– DiagramsDiagrams– Computer modelsComputer models

The Scientific MethodThe Scientific Method

• A way of thinking about and solving A way of thinking about and solving problemsproblems

• It is a logical methodIt is a logical method

• You do it all the timeYou do it all the time

Scientific MethodScientific Method

• A way of solving problems or A way of solving problems or answering questionsanswering questions

• Starts with observation- noting and Starts with observation- noting and recording factsrecording facts

• Hypothesis- an educated guess as to Hypothesis- an educated guess as to the cause of the problem or answer the cause of the problem or answer to the questionto the question

Scientific MethodScientific Method

• Experiment- designed to test the hypothesisExperiment- designed to test the hypothesis• Only two possible answers Only two possible answers • 1) hypothesis is right1) hypothesis is right• 2) hypothesis is wrong2) hypothesis is wrong• Generates data observations from Generates data observations from

experimentsexperiments• Modify hypothesis- repeat the cycle Modify hypothesis- repeat the cycle

The Scientific MethodThe Scientific Method

• Does not always work this way, but Does not always work this way, but gives a way of guiding our thinkinggives a way of guiding our thinking

• Hard part is testing only one variable Hard part is testing only one variable at a time.at a time.

• Changing only one thing at a timeChanging only one thing at a time

• If you change more than one, you If you change more than one, you don’t know which one is the causedon’t know which one is the cause

VariablesVariables

• Controlled experiment-Controlled experiment- Only want one Only want one thing to change at a time in a laboratory.thing to change at a time in a laboratory.

• Manipulated variable-Manipulated variable- What you change What you change or control directly or control directly

• Also called Also called independentindependent variable variable

• Responding variableResponding variable – What changes as – What changes as a result. No direct controla result. No direct control

• Also called Also called dependentdependent variable variable

Observations

Hypothesis

Experiment

• Cycle repeats many Cycle repeats many times.times.

• The hypothesis The hypothesis gets more and gets more and more certain.more certain.

• Becomes a Becomes a theorytheory

• A thoroughly tested A thoroughly tested model that explains model that explains why things behave why things behave a certain way.a certain way.

• Theory can never Theory can never be proven.be proven.

• Useful because Useful because they predict they predict behaviorbehavior

• Help us form Help us form mental pictures mental pictures of processes of processes ((modelsmodels))

Observations

Hypothesis

Experiment

• Another outcome is Another outcome is that certain that certain behavior is behavior is repeated many repeated many timestimes

• Scientific Scientific LawLaw is is developeddeveloped

• Description of how Description of how things behave things behave

• Law - howLaw - how

• Theory- whyTheory- why

Observations

Hypothesis

Experiment

Law

Theory(Model)

Prediction

Experiment

Modify

Observations

Hypothesis

Experiment

Law vs. TheoryLaw vs. Theory

Law Theory

Describes how

Explains why

Summarizes observations

Agrees with observations

Usually an equation

Predicts new discoveries

Law vs. TheoryLaw vs. Theory

• Theory can’t be proved; always the Theory can’t be proved; always the possibility that a new experiment will possibility that a new experiment will disprove a theorydisprove a theory

• Law described a natural Law described a natural phenomenon, but does not attempt phenomenon, but does not attempt to explain itto explain it

MeasurementMeasurement

• How do we measure in science?How do we measure in science?

• What do measurements mean?What do measurements mean?

• How do we tell?How do we tell?

• Let’s start with Accuracy vs. Let’s start with Accuracy vs. PrecisionPrecision

How good are the How good are the measurements?measurements?

• Scientists use two words to describe Scientists use two words to describe how good the measurements are-how good the measurements are-

• Accuracy- how close the Accuracy- how close the measurement is to the actual valuemeasurement is to the actual value

• Precision- how well can the Precision- how well can the measurement be repeatedmeasurement be repeated

DifferencesDifferences

• Accuracy can be true of an individual Accuracy can be true of an individual measurement or the average of measurement or the average of severalseveral

• Precision requires several Precision requires several measurements before anything can measurements before anything can be said about itbe said about it

Let’s use a golf anaolgy

Accurate? No

Precise? Yes

Accurate? Yes

Precise? Yes

Precise? No

Accurate? Maybe?

Accurate? Yes

Precise? We cant say!

ExamplesExamples

a.a. Multiple Multiple MeasurementsMeasurements

b.b. CorrectCorrect

c.c. RepeatableRepeatable

d.d. ReproducibleReproducible

e.e. Single Single MeasurementMeasurement

f.f. True ValueTrue Value

Scientific NotationScientific Notation

• To write in Scientific Notation you To write in Scientific Notation you need a number between 1 & 9 in front need a number between 1 & 9 in front of the decimal.of the decimal.

• When going from right to left you add When going from right to left you add the exponent (positive exponent)the exponent (positive exponent)

• When going from left to right you When going from left to right you subtract the exponent (negative subtract the exponent (negative exponent)exponent)

Converting Cont.Converting Cont.

• ExamplesExamples

I.I. 345345

II.II. .000345.000345

III.III. 5689056890

IV.IV. .000000000134.000000000134

The Metric SystemThe Metric System

MeasuringMeasuring

• The numbers are only half of a The numbers are only half of a measurementmeasurement

• It is 10 longIt is 10 long

• 10 What?????10 What?????

• Numbers without units are Numbers without units are meaninglessmeaningless

The Metric SystemThe Metric System

• Easier to use because it is a decimal Easier to use because it is a decimal systemsystem

• Every conversion is by some power of Every conversion is by some power of 1010

• A metric unit has two partsA metric unit has two parts

• A prefix and a base unitA prefix and a base unit

• Prefix tells you how many times to Prefix tells you how many times to divide or multiply by 10divide or multiply by 10

Base UnitsBase Units

• Length - meter more than a yard - Length - meter more than a yard - mm

• Mass - grams - a bout a raisin - Mass - grams - a bout a raisin - gg

• Time - second - Time - second - ss

• Temperature - Kelvin or ºCelsius Temperature - Kelvin or ºCelsius KK or or CC

• Energy - Joules- Energy - Joules- JJ

• Volume - Liter - half f a two liter bottle- Volume - Liter - half f a two liter bottle- LL

• Amount of substance - mole - Amount of substance - mole - molmol

PrefixesPrefixes

• kilo kilo kk 1000 times 1000 times

• deci deci dd 1/10 1/10

• centi centi cc 1/100 1/100

• milli milli mm 1/1000 1/1000

• kilometer - about 0.6 mileskilometer - about 0.6 miles

• centimeter - less than half an inchcentimeter - less than half an inch

• millimeter - the width of a paper clip millimeter - the width of a paper clip wire wire

VolumeVolume

• Calculated by multiplying L x W x HCalculated by multiplying L x W x H

• A liter volume of a cube 1 dm (10cm) A liter volume of a cube 1 dm (10cm) on a side….on a side….

• So 1L = 10cm x 10cm x 10cmSo 1L = 10cm x 10cm x 10cm

• 1L = 1000cm1L = 1000cm33

• 1/1000L = 1 cm1/1000L = 1 cm33

• 1mL = 1cm1mL = 1cm33

MassMass

• Weight is a force. Mass is the Weight is a force. Mass is the amount of matter.amount of matter.

• 1g is defined as the mass of 1 cm1g is defined as the mass of 1 cm33 of of water at 4 water at 4 00C.C.

• 1000g = 1000 cm1000g = 1000 cm33 of water of water

• 1kg = 1L of water1kg = 1L of water

ConvertingConverting

k h D d c m

• how far you have to move on this how far you have to move on this chart, tells you how far, and which chart, tells you how far, and which direction to move the decimal place.direction to move the decimal place.

• The box is the base unit, meters, The box is the base unit, meters, Liters, grams, etc.Liters, grams, etc.

ConversionsConversions

• Change 5.6 m to millimetersChange 5.6 m to millimeters

k h D d c m

starts at the base unit and move three to the right.move the decimal point three to the right

56 00

ConversionsConversions

• convert 25 mg to gramsconvert 25 mg to grams

• convert 0.45 km to mmconvert 0.45 km to mm

• convert 35 mL to litersconvert 35 mL to liters

• It works because the math works, we are dividing It works because the math works, we are dividing or multiplying by 10 the correct number of timesor multiplying by 10 the correct number of times

k h D d c m

Conversions

Change 5.6 km to millimeters

k h D d c m

Which is heavier?Which is heavier?

it dependsit depends

DensityDensity

• How heavy something is for its sizeHow heavy something is for its size

• The ratio of mass to volume for a The ratio of mass to volume for a substancesubstance

• D = M/VD = M/V

• Independent of how much of it you Independent of how much of it you havehave

• Gold- high densityGold- high density

• Air- low densityAir- low density

CalculatingCalculating

• The formula tells you howThe formula tells you how

• Units will be g/ml or g/cmUnits will be g/ml or g/cm33

• A piece of wood has a mass of 11.2g A piece of wood has a mass of 11.2g and a volume of 23mL. What is the and a volume of 23mL. What is the density?density?

• A piece of wood has a density of 0.93 A piece of wood has a density of 0.93 g/mL and a volume of 23 mL what is g/mL and a volume of 23 mL what is the mass?the mass?

FloatingFloating

• Lower density floats on higher Lower density floats on higher densitydensity

• Ice is less dense than waterIce is less dense than water

• Most wood is less dense than waterMost wood is less dense than water

• Helium is less dense than air.Helium is less dense than air.

• A ship is less dense than waterA ship is less dense than water

Density of WaterDensity of Water

• 1g of water is 1mL of water1g of water is 1mL of water

• Density of water is 1 g/mLDensity of water is 1 g/mL

• At 4At 400CC

• Otherwise it is less Otherwise it is less

Measuring TemperatureMeasuring Temperature

• Celsius scale.Celsius scale.

• water freezes at 0ºCwater freezes at 0ºC

• water boils at 100ºCwater boils at 100ºC

• body temperature 37ºCbody temperature 37ºC

• room temperature 20 - 25ºCroom temperature 20 - 25ºC

0ºC

Measuring TemperatureMeasuring Temperature

• Kelvin starts at absolute zero (-273 Kelvin starts at absolute zero (-273 º C)º C)

• degrees are the same sizedegrees are the same size

• C = K -273C = K -273

• K = C + 273K = C + 273

• Kelvin is always bigger.Kelvin is always bigger.

• Kelvin can never be negative. Kelvin can never be negative.

273 K

Temperature Temperature

• A measure of the average kinetic A measure of the average kinetic energyenergy

• Different temperature scales, all are Different temperature scales, all are talking about the same height of talking about the same height of mercury.mercury.

• Derive a equation for converting ºF Derive a equation for converting ºF toºCtoºC

Calculating Temp.Calculating Temp.

• From Celsius to Fahrenheit From Celsius to Fahrenheit

• F= (C x 9/5) + 32F= (C x 9/5) + 32

• From Fahrenheit to CelsiusFrom Fahrenheit to Celsius

• C= 5/9 (F-32)C= 5/9 (F-32)

• Examples:Examples:

I.I. 49 49 00F to F to 00CC

II.II. 97 97 00C to C to 00F F

Converting KelvinConverting Kelvin

• Converting Kelvin to CelsiusConverting Kelvin to Celsius

• K = C + 273K = C + 273

• Converting Celsius to KelvinConverting Celsius to Kelvin

• C = K – 273C = K – 273

• Why is there no conversion from Why is there no conversion from Kelvin to Fahrenheit?Kelvin to Fahrenheit?

ProblemsProblems

• How many????How many????

1.1. 349K to 349K to 00CC

2.2. 121200C to KC to K

3.3. 343400F to F to 00CC

4.4. 10110100C to C to 00FF

Temperature is differentTemperature is different

• from heat.from heat.

• Temperature is which way heat will Temperature is which way heat will flow. (from hot to cold)flow. (from hot to cold)

• Heat is energy, ability to do work.Heat is energy, ability to do work.

• A drop of boiling water hurts,A drop of boiling water hurts,

• kilogram of boiling water kills.kilogram of boiling water kills.