Chapter 3Chapter 3

MATTERMATTER

Section 3.1 Section 3.1 The Particulate Nature of MatterThe Particulate Nature of Matter

Objective:Objective: Learn about the composition of matterLearn about the composition of matter

MatterMatterMatterMatter is anything that: is anything that: a) has mass, a) has mass, andand b) takes up spaceb) takes up space

Mass Mass = a measure of the amount of = a measure of the amount of “stuff” (or material) the object contains “stuff” (or material) the object contains (don’t confuse this with weight, a (don’t confuse this with weight, a measure of gravity)measure of gravity)

VolumeVolume = a measure of the space = a measure of the space occupied by the objectoccupied by the object

States of Matter

Objective:Objective: To define the 3 states of matterTo define the 3 states of matter

States of matterStates of matter

1)1) SolidSolid- matter that can not flow (definite - matter that can not flow (definite shape) and has definite volume.shape) and has definite volume.

2)2) LiquidLiquid- definite volume but takes the - definite volume but takes the shape of its container (flows).shape of its container (flows).

3)3) GasGas- a substance without definite volume - a substance without definite volume or shape and can flow.or shape and can flow.

* VaporVapor- a substance that is currently a gas, - a substance that is currently a gas, but normally is a liquid or solid at room but normally is a liquid or solid at room temperature. (Which is correct: “water gas”, temperature. (Which is correct: “water gas”, or “water vapor”?)or “water vapor”?)

States of MatterStates of Matter

Solid

Liquid

Gas

Definite Volume?

YES

YES

NO

Definite Shape?

YES

NO

NO

Result of a TemperatureIncrease?

Small Expands.

Small Expands.

Large Expands.

Will it Compress?

NO

NO

YES

Three Main PhasesThree Main Phases

Solids – molecule are locked into fixed positions….little movement to move

Liquids – molecules can slide past one another

Gas – a free to move randomly about

Copper Phases - SolidCopper Phases - Solid

Copper Phases - LiquidCopper Phases - Liquid

Copper Phases – Vapor (gas)Copper Phases – Vapor (gas)

Solid Liquid Gas

Melt Evaporate

CondenseFreeze

44thth state: state: PlasmaPlasma - - formed at formed at high temperatures; ionized phase high temperatures; ionized phase

of matter as found in the sunof matter as found in the sun

Ever heard of a Bose-Einstein Ever heard of a Bose-Einstein Condensate???Condensate???

http://www.pbs.org/wgbh/nova/physics//nova/physics/ultracold-atoms.html ultracold-atoms.html

Section 3.2Section 3.2Physical/Chemical Properties and ChangesPhysical/Chemical Properties and Changes

Objective:Objective: To distinguish between physical and chemical To distinguish between physical and chemical

propertiesproperties To distinguish between physical and chemical To distinguish between physical and chemical

changeschanges

Properties are…Properties are…

Words that describe matter (adjectives)Words that describe matter (adjectives)Physical PropertiesPhysical Properties-- a property that can be a property that can be observed and measured without changing observed and measured without changing the material’s composition.the material’s composition.Describes individual characteristicsDescribes individual characteristicsExamples- color, hardness, m.p., b.p.Examples- color, hardness, m.p., b.p.Chemical PropertiesChemical Properties-- a property that can a property that can only be observed by changing the only be observed by changing the composition of the material. composition of the material. Describes social characteristicsDescribes social characteristicsExamples- ability to burn, decompose, Examples- ability to burn, decompose, ferment, react with, etc.ferment, react with, etc.

Physical vs. Chemical ChangePhysical vs. Chemical ChangePhysical changePhysical change will change the visible will change the visible appearance, without changing the appearance, without changing the composition of the material.composition of the material. Boil, melt, cut, bend, split, crackBoil, melt, cut, bend, split, crack Is boiled water still water?Is boiled water still water?

Can be Can be reversiblereversible, or , or irreversibleirreversible

Chemical changeChemical change - a change where a - a change where a new form of matter is formed.new form of matter is formed. Rust, burn, decompose, fermentRust, burn, decompose, ferment

Recognizing Chemical ChangesRecognizing Chemical Changes

1)1) EnergyEnergy is absorbed or released is absorbed or released (temperature changes (temperature changes hotter or colderhotter or colder))

2)2) ColorColor changeschanges

3)3) GasGas production (bubbling, fizzing, or odor production (bubbling, fizzing, or odor change; smoke)change; smoke)

4)4) formation of aformation of a precipitateprecipitate - a solid that - a solid that separates from solution (won’t dissolve)separates from solution (won’t dissolve)

5)5) IrreversibilityIrreversibility - not easily reversed- not easily reversed

But, there are examples of these that are not But, there are examples of these that are not chemical – boiling water bubbles, etc.chemical – boiling water bubbles, etc.

Section 3.5Separation of Mixtures

Objective:Objective: Learn 2 methods of separating a mixtureLearn 2 methods of separating a mixture

Separation of a Mixture

Objective:Objective: Learn 2 methods of separating mixturesLearn 2 methods of separating mixtures

Separating Mixtures- Separating Mixtures- (talk more about mixtures is tomorrow)(talk more about mixtures is tomorrow)

Some mixtures can be separated Some mixtures can be separated easily by physical means: rocks and easily by physical means: rocks and marbles, iron filings and sulfur (use marbles, iron filings and sulfur (use magnet) magnet)

Differences in physical properties Differences in physical properties can be used to separate mixtures.can be used to separate mixtures.

FiltrationFiltration - separates a solid from the - separates a solid from the liquid in a heterogeneous mixture (by liquid in a heterogeneous mixture (by size) – size) – Figure 2.7, page 46 Figure 2.7, page 46

Filtration Filtration separates a separates a liquid from a liquid from a

solid.solid.

Separation of a MixtureSeparation of a MixtureDistillation: takes advantage of different boiling points.

NaCl boils at 1415 oC

Another view of Distillation

Separation of a sand-saltwater mixtureSeparation of a sand-saltwater mixture

To separate sand-saltwater mixture:

first use filtration to separate sand from saltwater

then use distillation to separate salt and water

Section 3.3Section 3.3Elements and CompoundsElements and Compounds

Objective:Objective: The difference between a element & compoundThe difference between a element & compound

What about atoms?What about atoms?All matter is made up of All matter is made up of tiny particles called tiny particles called ATOMSATOMS

Although objects look Although objects look quite continuous and quite continuous and uniform, they are really uniform, they are really particulate in natureparticulate in nature

Atoms are not all alikeAtoms are not all alike

About 100 different types About 100 different types of atoms make up all the of atoms make up all the different types of matterdifferent types of matter

Think of the alphabet Think of the alphabet (atoms) and words (matter)(atoms) and words (matter)

Element, Compound or MoleculeElement, Compound or MoleculeElements simplest kind of matter simplest kind of matter

cannot be broken down any simpler and still have cannot be broken down any simpler and still have properties of that element!properties of that element!

all all oneone kind of atom. kind of atom.

CompoundsCompounds are substances that can be broken down are substances that can be broken down onlyonly by chemical methods by chemical methods when broken down, the pieces have completely when broken down, the pieces have completely

different properties than the original compound.different properties than the original compound. made of made of two or moretwo or more different different atoms, chemically atoms, chemically

combined (not just a physical blend!)combined (not just a physical blend!)

Molecules Molecules are substances that can be broken down are substances that can be broken down onlyonly by chemical methodsby chemical methods made of made of two or moretwo or more atoms, chemically atoms, chemically

combined (not just a physical blend!)combined (not just a physical blend!)

A A molecule molecule is what you get when any atoms join together.is what you get when any atoms join together.A A compoundcompound is what you get when atoms of two or more is what you get when atoms of two or more different elements join together.different elements join together.All compounds are molecules, but not all molecules are All compounds are molecules, but not all molecules are compounds.compounds.Water is a molecule because it is made from atoms that Water is a molecule because it is made from atoms that have been chemically combined. It is also a compound have been chemically combined. It is also a compound because the atoms that make water are not all the same - because the atoms that make water are not all the same - some are some are oxygen and some are hydrogen.Oxygen in the atmosphere is a molecule because it is Oxygen in the atmosphere is a molecule because it is made from two atoms of oxygen. It is not a compound made from two atoms of oxygen. It is not a compound because it is made from atoms of only one element - because it is made from atoms of only one element - oxygen. This type of molecule is called a diatomic oxygen. This type of molecule is called a diatomic molecule, a molecule made from two atoms of the same molecule, a molecule made from two atoms of the same type.type.

I am not clear on what a molecule is. If water is a molecule, is it also a I am not clear on what a molecule is. If water is a molecule, is it also a compound because the hydrogen and oxygen have been chemically compound because the hydrogen and oxygen have been chemically combined? If so, how do you determine whether a substance is a compound combined? If so, how do you determine whether a substance is a compound or a molecule?or a molecule?

Elements vs CompoundsElements vs Compounds

Currently, there are Currently, there are 117117 elementselements

ElementsElements have a 1 or two letter have a 1 or two letter symbol, and and compoundscompounds have a formula. have a formula.

An An element’s first letter always capitalized; ; if there is a second letter, , it is written lowercase: B, Ba, C, Ca, H, He: B, Ba, C, Ca, H, He

Some names come from Latin or other Some names come from Latin or other languageslanguages

Compounds vs ElementsCompounds vs Elements

Compounds can be broken down into be broken down into simpler substances by chemical means, simpler substances by chemical means, but but elements cannot.

Compounds always contain atoms of different elements…..Always in the same composition Ex. Water is always found as 2

hydrogen atoms combined with 1 oxygen atom

Section 3.4Mixtures vs Pure substanceMixtures vs Pure substance

Objective:Objective: To distinguish between mixtures and pure To distinguish between mixtures and pure

substancessubstances

MixturesMixturesMixtures - - are a physical blendare a physical blend of at of at least two substances; have variable least two substances; have variable composition. They can be either:composition. They can be either:

1)1) HeteroHeterogeneousgeneous – the mixture – the mixture differentdifferent it is not uniform in compositionit is not uniform in composition

• Chocolate chip cookie, gravel, soil.Chocolate chip cookie, gravel, soil.

2.) HomoHomogeneousgeneous - - samesame composition composition throughout; called “throughout; called “solutionssolutions””

• Kool-aid, air, salt waterKool-aid, air, salt water

Every part keeps it’s own properties.Every part keeps it’s own properties.

Solutions are homogeneous mixturesSolutions are homogeneous mixturesMixed molecule by molecule, thus too Mixed molecule by molecule, thus too small to see the different partssmall to see the different parts

Can occur between any state of Can occur between any state of matter: gas in gas; liquid in gas; gas matter: gas in gas; liquid in gas; gas in liquid; solid in liquid; solid in solid in liquid; solid in liquid; solid in solid (alloys), etc.(alloys), etc.

Thus, based on the distribution of Thus, based on the distribution of their components, mixtures are called their components, mixtures are called homogeneoushomogeneous or or heterogeneousheterogeneous..

Alloy – mixture of metalsAlloy – mixture of metals

Twenty-four-karat gold is an elementTwenty-four-karat gold is an element Eighteen-karat gold is an alloy. Eighteen-karat gold is an alloy. Fourteen-karat gold is an alloy. Fourteen-karat gold is an alloy.

**An alloy is a mixture or metallic solid solution composed of two or more elements

Tie together some of the Tie together some of the informationinformation

What is the difference then What is the difference then between a mixture and a between a mixture and a

compound????compound????

Compound vs. MixtureCompound vs. Mixture

Compound Mixture

Made of one kindof material

Made of more thanone kind of material

Made by a chemical change

Made by a physical change

Definitecomposition

Variablecomposition

Pure SubstancesPure Substances

Pure substancesPure substances – always have same – always have same compositioncomposition Either elements Either elements oror compounds compounds

Ex pure water is a pure substance – it only Ex pure water is a pure substance – it only contains Hcontains H22O moleculesO molecules

Tap water is a mixture – it contains HTap water is a mixture – it contains H22O and other O and other

minerals such as calcium and magnesiumminerals such as calcium and magnesium

Classification of MatterClassification of Matter

Which is it?Which is it?

Element

Which is it?

Compound/molecule

Which is it?

Mixture

Which is it?

Molecule.

CANNOT be a compound. WHY????

Chapter 3Chapter 3

The EndThe End