chapter 3 matter. section 3.1 the particulate nature of matter objective: learn about the...
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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
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
Separation of a MixtureSeparation of a MixtureDistillation: takes advantage of different boiling points.
NaCl boils at 1415 oC
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