Yesterday, we asked “are all Yesterday, we asked “are all chemicals bad?”chemicals bad?”
No, but some can be dangerousNo, but some can be dangerous Chemicals are everywhereChemicals are everywhere
Which brings us to…Which brings us to…
What is What is ChemistryChemistry?? the study of matter and the changes the study of matter and the changes
that it undergoes.that it undergoes.
What is What is MatterMatter?? anything that has mass and takes up anything that has mass and takes up
space space
What is What is MassMass?? a measurement of the amount of a measurement of the amount of
matter in an object matter in an object
Mass verses WeightMass verses Weight
They are related, but what’s the They are related, but what’s the difference?difference?
MassMass is universal, is universal, weightweight depends on depends on gravitygravity
WeightWeight = = massmass times the gravitational pull times the gravitational pull
Branches of ChemistryBranches of Chemistry
OrganicOrganic InorganicInorganic AnalyticalAnalytical PhysicalPhysical BiochemicalBiochemical
OrganicOrganic
Area of EmphasisArea of Emphasis Most Most carboncarbon-containing chemicals-containing chemicals
Examples:Examples: PharmaceuticalsPharmaceuticals PlasticsPlastics
InorganicInorganic Area of EmphasisArea of Emphasis
In general, matter that does In general, matter that does notnot contain carboncontain carbon
Examples:Examples: MineralsMinerals MetalsMetals and and nonmetals nonmetals Semi-conductorsSemi-conductors
AnalyticalAnalytical
Area of EmphasisArea of Emphasis ComponentsComponents and and compositioncomposition of of
substancessubstances
Examples:Examples: Food NutrientsFood Nutrients Quality ControlQuality Control
PhysicalPhysical
Area of EmphasisArea of Emphasis The The behaviorbehavior and and changeschanges of of
matter and the related matter and the related energyenergy changeschanges
Examples:Examples: Reaction Reaction RatesRates Reaction Reaction MechanismsMechanisms
BiochemicalBiochemical
Area of EmphasisArea of Emphasis MatterMatter and and processesprocesses of living of living
organismsorganisms
Examples:Examples: MetabolismMetabolism FermentationFermentation
Next, the Scientific Next, the Scientific MethodMethod
Why do we have the Why do we have the scientific method?scientific method?
Gives us Gives us logicallogical steps to follow to steps to follow to assist us in answering a assist us in answering a questionquestion..
What are the “steps”?What are the “steps”?
Develop a Develop a questionquestion Conduct background Conduct background researchresearch Form a Form a hypothesishypothesis Test with an Test with an experimentexperiment Make Make observationsobservations and collect and collect datadata Analyze the Analyze the resultsresults Draw Draw conclusionsconclusions ReportReport results and test again results and test again
Parts of an experimentParts of an experiment
IndependentIndependent Variable Variable
PPart of the experiment that the scientist changes
What is being tested There is only one independent variable at
a time.
What I change
DependentDependent Variable Variable
PPart of the experiment that changes because of the
independent variable
ControlControl
PPart of the experiment that does not receive the independent
variable
ConstantsConstants
PPart of the experiment that remain the same for every part of the
experiment
Types of DataTypes of Data
QuantitativeQuantitative Data that is Data that is numericalnumerical in nature in nature
QualitativeQualitative Data that is Data that is descriptivedescriptive in nature in nature
An example experimentAn example experiment A person wants to test whether music can A person wants to test whether music can
help make plants grow. The person plants help make plants grow. The person plants several seeds from the same batch into several seeds from the same batch into identical flower pots with identical potting identical flower pots with identical potting soil, watering schedule and light supply. soil, watering schedule and light supply. One flower pot is isolated from the sound One flower pot is isolated from the sound supply, while the other pots are subjected supply, while the other pots are subjected to various types of music. After 1 month, to various types of music. After 1 month, the “healthiness” of each plant is the “healthiness” of each plant is measured.measured.