unit 2 matter and change. obj. 1…pure substances vs. mixtures matter: anything that takes up space...

UNIT 2UNIT 2Matter and ChangeMatter and Change

Obj. 1…Pure Obj. 1…Pure Substances vs. Substances vs.

MixturesMixturesMatter: anything that takes up space and has Matter: anything that takes up space and has

mass.mass.

Matter can be uniform throughout Matter can be uniform throughout ((homogeneoushomogeneous) or non-uniform throughout ) or non-uniform throughout ((heterogeneousheterogeneous))

Two categories of matter: Two categories of matter: Pure substances Pure substances MixturesMixtures

Pure Pure Substances:Substances:

have a definite composition have a definite composition

written as symbol or formulawritten as symbol or formula

homogenous (looks same throughout) homogenous (looks same throughout)

Obj. 1 cont…Obj. 1 cont…(elements(elements or or compounds)compounds)

1 capital letter1 capital letter 2 or more capital letters2 or more capital letters

Elements:Elements: composed of one type of atomcomposed of one type of atom

copper wirecopper wire aluminum foilaluminum foil silversilver goldgold

composed of 2 or more elements that are composed of 2 or more elements that are chemically bonded together. chemically bonded together.

they can be broken down only through they can be broken down only through chemical changeschemical changes..

CompoundCompounds:s:

waterwater

ExamplesExamples……

Obj. 1 cont…Obj. 1 cont…

salt salt (NaCl)(NaCl) carbon dioxide carbon dioxide

(CO(CO22))

sand (SiOsand (SiO22))

(different properties than pure (different properties than pure elements)elements)

Same elements but two different compounds, Same elements but two different compounds, each with a definite composition.each with a definite composition.

For example…For example…Obj. 1 cont…Obj. 1 cont…

MixtureMixtures:s:

composed of two or more different pure composed of two or more different pure substancessubstances

cannot be identified by chemical formulascannot be identified by chemical formulas

can be separated through can be separated through physicalphysical means means

can be homogeneous or heterogeneouscan be homogeneous or heterogeneous

Obj. 1 cont…Obj. 1 cont…

heterogeneous mixtureheterogeneous mixture homogeneous mixturehomogeneous mixture

solutions, suspensions and colloidssolutions, suspensions and colloids

Obj. 1 cont…Obj. 1 cont…Three types of mixtures:Three types of mixtures:

homogenoushomogenous heterogeneousheterogeneous

Three states (phases) of Three states (phases) of matter:matter:

solidssolids liquidsliquids gasesgases

** mixtures can be composed of any combo. of ** mixtures can be composed of any combo. of these!these!

Obj. 1 cont…Obj. 1 cont…Pure or Mixture?!?!Pure or Mixture?!?!

1. Kool-aid1. Kool-aid

2. distilled 2. distilled waterwater

3. tap water3. tap water

4. chocolate chip cookie4. chocolate chip cookie

5. oxygen gas5. oxygen gas

6. atmosphere6. atmosphere

7. Glucose (C7. Glucose (C66HH1212OO66))

mixturemixture

mixturemixture

mixturemixture

mixturemixture

purepure

purepure

purepure

Obj. 2…Homogenous Obj. 2…Homogenous MatterMatterThree classes of homogenous Three classes of homogenous

matter:matter: 1. elements1. elements2. compounds2. compounds3. solutions3. solutions

purepure

mixturmixtureeObj. 3-4…Classification Obj. 3-4…Classification

of Matterof Matter ElemenElemen

t:t: cannot be broken down – only 1 type cannot be broken down – only 1 type

of atomof atom- one cap. letter- one cap. letter CompouCompou

nd:nd: chemically separated into chemically separated into

elementselements- 2 or more cap. letter- 2 or more cap. letter Mixture:Mixture: variable composition…no formula!variable composition…no formula!

Obj. 3-4 cont…Obj. 3-4 cont…Element, Compound or Element, Compound or Mixture?!?!Mixture?!?!

1. silver1. silver

2. pine 2. pine treetree

3. orange juice3. orange juice

4. phosphorus4. phosphorus

5. iced tea5. iced tea

6. Acetaminophen (aspirin) 6. Acetaminophen (aspirin) CC88HH99OO22NN

elemenelementt

elemenelementt

mixturemixture

mixturemixture

mixturemixture

compoucompoundnd

Obj. 5…Metals, Non-Obj. 5…Metals, Non-Metals and MetalloidsMetals and MetalloidsMetalsMetals……

conduct electricityconduct electricity

lose e-lose e-

malleablmalleablee

(can be hammered)(can be hammered)

(cations)(cations)

ductileductile(can be drawn into a wire)(can be drawn into a wire)

lustrouslustrous(shiny)(shiny)

mostly solidsmostly solids

Nickel (Ni)Nickel (Ni)

Obj. 5 cont…Obj. 5 cont…Non-Non-Metals…Metals…

don’t conduct don’t conduct electricityelectricity

gain e-gain e-(anions)(anions)

dulldull(no luster)(no luster)

usually gaseoususually gaseous

Metalloids…Metalloids… properties of both metals and non-properties of both metals and non-

metalsmetals

friablefriable

can lose or gain e-can lose or gain e- some conduct electricitysome conduct electricity

Sulfur (S)Sulfur (S)

Silicon (Si)Silicon (Si)

(shatters easily)(shatters easily)

Obj. 6…Organic vs. Obj. 6…Organic vs. InorganicInorganic

OrganicOrganic compounds contain compounds contain carboncarbon (element of (element of life)life)

Ex…Ex…

glucose (Cglucose (C66HH1212OO66))

methane (CHmethane (CH44))

** Exceptions to the carbon rule…** Exceptions to the carbon rule… carbon monoxide (CO)carbon monoxide (CO)

carbon dioxide (COcarbon dioxide (CO22))

carbonate ion (COcarbonate ion (CO33-1-1))

** these exceptions and any compound w/out ** these exceptions and any compound w/out carbon arecarbon are INORGANICINORGANIC ****

Obj. 7…Heterogeneous Obj. 7…Heterogeneous vs. Homogenousvs. Homogenous

homogenoushomogenous substances are completely substances are completely uniform throughout.uniform throughout.

elementselements

(cannot distinguish the different parts)(cannot distinguish the different parts)

compouncompoundsds solutionssolutions

heterogeneousheterogeneous substances are non-uniform substances are non-uniform throughout.throughout.(can distinguish the different parts)(can distinguish the different parts)

colloidscolloids

suspensisuspensionsons

purepure

mixturmixturee

mixturesmixtures

Obj. 7 cont…Obj. 7 cont…

homogeneoushomogeneous heterogeneousheterogeneous

Obj. 8…Solutions, Obj. 8…Solutions, Suspensions & ColloidsSuspensions & Colloids

Solutions…Solutions… smallest particle size (< 1 nanometer 10smallest particle size (< 1 nanometer 10-9-9

meter)meter) homogenouhomogenou

ss particles do not settle out on particles do not settle out on standingstanding

~ particles can pass through membrane and ~ particles can pass through membrane and filter paperfilter paper

does not display Tyndall Effect does not display Tyndall Effect (scattering of (scattering of light)light)

Ex…Ex…

salt salt waterwater

(salt and water)(salt and water)

unopenedunopened soft drinksoft drink(water, syrup, CO(water, syrup, CO22 etc…) etc…)

Obj. 8 cont…Obj. 8 cont…SuspensionsSuspensions……

largest particle size (> 100 nanometers)largest particle size (> 100 nanometers)

heterogeneheterogeneousous particles settle out on standingparticles settle out on standing

~ particles separated by membrane and filter ~ particles separated by membrane and filter paperpaper

does display Tyndall Effect does display Tyndall Effect (scattering of (scattering of light)light)

~ colloid is left after settling~ colloid is left after settling

Ex…Ex…

muddy watermuddy water

salad dressingsalad dressing

Obj. 8 cont…Obj. 8 cont…Colloids…Colloids…

medium particle size (1-100 nanometers)medium particle size (1-100 nanometers)

heterogeneheterogeneousous particles do not settle out on particles do not settle out on standingstanding

~ particles separated by membrane, NOT filter ~ particles separated by membrane, NOT filter paperpaper

does display Tyndall Effect does display Tyndall Effect (scattering of (scattering of light)light)

Ex…Ex…

milkmilk

fogfog

Obj. 9…Tyndall Effect Obj. 9…Tyndall Effect and Brownian Motionand Brownian Motion

The The Tyndall EffectTyndall Effect can be seen in mixtures can be seen in mixtures whose particles are large enough to scatter whose particles are large enough to scatter light.light.~ can see a beam of light through the ~ can see a beam of light through the

mixturemixture~ seen in ~ seen in colloidscolloids and and suspensionssuspensions

Tyndall Effect… Tyndall Effect…

Obj. 9 cont…Obj. 9 cont… Brownian motionBrownian motion is the constant movement is the constant movement

of particles in a mixture due to kinetic of particles in a mixture due to kinetic energy.energy.

~ why solutions and colloids don’t settle ~ why solutions and colloids don’t settle out.out.

Obj. 10…Parts of a Obj. 10…Parts of a SolutionSolution

all solutions are composed of two parts…all solutions are composed of two parts…

~ ~ solutsolutee

……substance that gets dissolvedsubstance that gets dissolved

~ ~ solvesolventnt

……substance that does the dissolvingsubstance that does the dissolving

** the solvent ALWAYS occurs in the greater ** the solvent ALWAYS occurs in the greater quantity!quantity!Ex…Ex…

salt water…salt water…

~ ~ solute solute = = saltsalt~ ~ solventsolvent = = waterwater