The Matter

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Chemistry: The Study of MatterChemistry: The Study of Matter

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What is Chemistry?What is Chemistry?

The study of the The study of the matter, its composition, matter, its composition, properties, and the properties, and the changes it undergoes.changes it undergoes.

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Types of ChemistryTypes of Chemistry Analytical Chemistry studies Analytical Chemistry studies

composition of substances.composition of substances. Inorganic Chemistry substances without Inorganic Chemistry substances without

carboncarbon Organic Chemistry compounds Organic Chemistry compounds

containing carboncontaining carbon Biochemistry- Chemistry of living thingsBiochemistry- Chemistry of living things Physical Chemistry studies behavior of Physical Chemistry studies behavior of

substancessubstances

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Scientific MethodScientific Method A way of solving problems or answering A way of solving problems or answering

questions.questions. Starts with observation- noting an Starts with observation- noting an

recording factsrecording facts Hypothesis- an Hypothesis- an educatededucated guess as to guess as to

the cause of the problem or answer to the cause of the problem or answer to the question. the question. (Some research is (Some research is involved to make this guess)involved to make this guess)

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Scientific MethodScientific Method ExperimentExperiment- designed to test the - designed to test the

hypothesishypothesis only two possible answersonly two possible answers

– hypothesis is righthypothesis is right

– hypothesis is wronghypothesis is wrong Generates data observations from Generates data observations from

experiments.experiments. Modify hypothesis - repeat the cycleModify hypothesis - repeat the cycle

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Observations

Hypothesis

Experiment

Cycle repeats many Cycle repeats many times.times.

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

Becomes a Becomes a theorytheory A thoroughly tested A thoroughly tested

model that explains model that explains why things behave a why things behave a certain way.certain way.

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

Useful because Useful because they predict they predict behaviorbehavior

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

Observations

Hypothesis

Experiment

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

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Law

Theory(Model)

Prediction

Experiment

Modify

Observations

Hypothesis

Experiment

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What is Matter?What is Matter?MatterMatter is anything that is anything that

takes up space and has takes up space and has mass.mass.

MassMass is the amount of is the amount of matter in an object.matter in an object.

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Types of MatterTypes of Matter SubstanceSubstance- a particular kind of matter – - a particular kind of matter –

purepure

– ElementsElements

– CompoundsCompounds Mixture-Mixture- more than one kind of matter more than one kind of matter

– Heterogeneous MixturesHeterogeneous Mixtures

– Homogeneous MixturesHomogeneous Mixtures

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PropertiesProperties Words that describe matter (adjectives)Words that describe matter (adjectives) Physical PropertiesPhysical Properties- a property that can - a property that can

be observed and measured without be observed and measured without changing the substance.changing the substance.

Examples?Examples? Chemical PropertiesChemical Properties- a property that - a property that

can only be observed by changing the can only be observed by changing the type of substance. type of substance.

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States of matterStates of matter SolidSolid- mater that can not flow and has - mater that can not flow and has

definite volume.definite volume. LiquidLiquid- definite volume but takes the - definite volume but takes the

shape of its container (flows).shape of its container (flows). GasGas- a substance without definite - a substance without definite

volume or shape and can flow.volume or shape and can flow. VaporVapor- a substance that is currently a - a substance that is currently a

gas but normally is a liquid or solid at gas but normally is a liquid or solid at room temperature.room temperature.

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States of MatterStates of Matter

Solid

Liquid

Gas

Definite Volume?

YES

YES

NO

Definite Shape?

YES

NO

NO

Temp. increase

Small Expans.

Small Expans.

Large Expans.

Com-pressible?

NO

NO

YES

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Solid Liquid Gas

Melt Evaporate

CondenseFreeze

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Physical ChangesPhysical Changes A change that changes appearances, A change that changes appearances,

without changing the composition.without changing the composition. Examples?Examples? Boiled water is still water.Boiled water is still water. Chemical changes - a change where a Chemical changes - a change where a

new form of matter is formed.new form of matter is formed. Examples?Examples?

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MixturesMixtures Made up of two substances.Made up of two substances. Variable composition?Variable composition? HeterogeneousHeterogeneous- mixture is not the same - mixture is not the same

from place to place.from place to place. Chocolate chip cookie, gravel, soil.Chocolate chip cookie, gravel, soil. HomogeneousHomogeneous- same composition - same composition

throughout.throughout. Kool-aid, air.Kool-aid, air. Every part keeps its properties.Every part keeps its properties.

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SolutionsSolutions Homogeneous mixtureHomogeneous mixture Mixed molecule by moleculeMixed molecule by molecule Can occur between any state of matter.Can occur between any state of matter. Solid in liquid- Kool-aidSolid in liquid- Kool-aid Liquid in liquid- antifreezeLiquid in liquid- antifreeze Gas in gas- airGas in gas- air Solid in solid - brassSolid in solid - brass Liquid in gas- water vaporLiquid in gas- water vapor

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SolutionsSolutions Like all mixtures, they keep the Like all mixtures, they keep the

properties of the components.properties of the components. Can be separated by physical meansCan be separated by physical means Not easily separated- Not easily separated- cancan be separated. be separated.

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SubstancesSubstances ElementsElements- simplest kind of matter- simplest kind of matter Cannot be broken down into simplerCannot be broken down into simpler All one kind of atom.All one kind of atom. CompoundsCompounds are substances that can be are substances that can be

broken down by chemical methodsbroken down by chemical methods When they are broken down, the pieces When they are broken down, the pieces

have completely different properties have completely different properties than the compound.than the compound.

Made of Made of moleculesmolecules- two or more atoms - two or more atoms

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Compound or MixtureCompound or Mixture

Compound Mixture

One kind of piece-Molecules

More than one kind - Molecule or atoms

Making is a chemical change

Making is a physical change

Only one kind Variable composition

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Which is it?Which is it?

ElementCompoundMixture

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Chemical symbolsChemical symbols There are 109 elementsThere are 109 elements Each has a 1 or two letter Each has a 1 or two letter symbolsymbol First letter always capitalized second First letter always capitalized second

nevernever Don’t need to memorizeDon’t need to memorize Some from Latin of other languagesSome from Latin of other languages

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EnergyEnergy The ability to do The ability to do work.work. Work - Work - cause a change or move an cause a change or move an

object.object. Many types- all can be changed into the Many types- all can be changed into the

other.other.

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Types of energyTypes of energy Potential- stored energyPotential- stored energy Kinetic Energy- energy something has Kinetic Energy- energy something has

because its movingbecause its moving Heat- the energy that moves because of Heat- the energy that moves because of

a temperature difference.a temperature difference. Chemical energy- energy released or Chemical energy- energy released or

absorbed in a chemical change.absorbed in a chemical change. Electrical energy - energy of moving Electrical energy - energy of moving

chargescharges

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Types of EnergyTypes of Energy Radiant Energy- energy that can travel Radiant Energy- energy that can travel

through empty space (light, UV, through empty space (light, UV, infrared, radio)infrared, radio)

All types of energy can be converted All types of energy can be converted into others.into others.

If you trace the source far enough back, If you trace the source far enough back, you will end up at nuclear energy.you will end up at nuclear energy.

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Conservation of EnergyConservation of Energy Energy can be neither created or Energy can be neither created or

destroyed in ordinary changes (not destroyed in ordinary changes (not nuclear), it can only change form.nuclear), it can only change form.

Its not just a good idea, its the Its not just a good idea, its the lawlaw..

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Chemical ReactionsChemical Reactions When one or more substances are When one or more substances are

changed into new substances.changed into new substances. Reactants- stuff you start withReactants- stuff you start with Products- What you makeProducts- What you make NEW PROPERTIESNEW PROPERTIES Not easily reversedNot easily reversed

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Indications of a chemical reactionIndications of a chemical reaction Energy absorbed or releasedEnergy absorbed or released Color changeColor change odor changeodor change PrecipitatePrecipitate- solid that separates from - solid that separates from

solutionsolution Not easily reversedNot easily reversed

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Conservation of Mass Conservation of Mass Mass can not be created or destroyed Mass can not be created or destroyed

in ordinary (not nuclear) changes.in ordinary (not nuclear) changes. All the mass can be accounted for.All the mass can be accounted for.

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What about nuclear?What about nuclear? E = mcE = mc22 energy = mass x (speed of light)energy = mass x (speed of light)22 speed of light = 3 x 10speed of light = 3 x 1088 A little mass can make a lot of energyA little mass can make a lot of energy Law of Conservation of Mass - EnergyLaw of Conservation of Mass - Energy

the total of the mass and energy the total of the mass and energy remains the same in any changeremains the same in any change