18.2 18.2 –– Properties of Properties of MatterMatter

ObjectivesObjectives

Identify substances using physical Identify substances using physical properties.properties.

Contrast physical and chemical propertiesContrast physical and chemical properties Compare and contrast physical and Compare and contrast physical and

chemical changes.chemical changes. Identify chemical changes.Identify chemical changes. Determine how the law of conservation of Determine how the law of conservation of

mass applies to chemical changes.mass applies to chemical changes.

PropertiesProperties

Physical Physical –– characteristics that can be characteristics that can be observed without altering identity of observed without altering identity of substancesubstance Density, color, melting pointDensity, color, melting point

Chemical Chemical –– characteristics that cannot be characteristics that cannot be observed without altering identity of observed without altering identity of substancesubstance FlammabilityFlammability

Changes in matterChanges in matter

Physical Physical –– alterations in form but not alterations in form but not matter itselfmatter itself Does not alter identityDoes not alter identity Tear, Break, Grind, Dissolve, Freeze, Melt, Tear, Break, Grind, Dissolve, Freeze, Melt,

Boil, Distill, CrushBoil, Distill, Crush

Chemical Chemical –– does alter identity does alter identity Produces different substanceProduces different substance Burn, Cook, Rust, Decay, DigestBurn, Cook, Rust, Decay, Digest

DistillationDistillation

Signs of Chemical ChangeSigns of Chemical Change

1.1. Color ChangeColor Change

2.2. Bubbles Bubbles –– gas produced gas produced

3.3. Odor changeOdor change

4.4. Temperature changeTemperature change

5.5. Precipitate forms Precipitate forms –– new solid made new solid made

WeatheringWeathering

Forces of nature are continuously shaping Forces of nature are continuously shaping the Earththe Earth’’s surfaces surface Rocks splitRocks split Deep canyons are carved outDeep canyons are carved out Sand dunes shiftSand dunes shift Curious limestone formations decorate cavesCurious limestone formations decorate caves

Physical & Chemical ChangePhysical & Chemical Change

Start here 5thStart here 5th

Weathering - PhysicalWeathering - Physical

Large rocks split as water seeps through Large rocks split as water seeps through small crackssmall cracks Water freezes and expandsWater freezes and expands

Smaller pieces of newly exposed rock still Smaller pieces of newly exposed rock still have same properties of original rockhave same properties of original rock

Weathering - ChemicalWeathering - Chemical

Limestone, calcium carbonate, does not Limestone, calcium carbonate, does not dissolve easily in waterdissolve easily in water

If water is slightly acidic because of the If water is slightly acidic because of the presence of carbon dioxide it reacts with presence of carbon dioxide it reacts with limestonelimestone

This change creates a new substance, This change creates a new substance, calcium hydrogen carbonate, which calcium hydrogen carbonate, which dissolves in waterdissolves in water

Weathering - ChemicalWeathering - Chemical

Similar chemical Similar chemical change produces change produces caves and icicle caves and icicle shaped rock shaped rock formationsformations

Law of Conservation of MassLaw of Conservation of Mass

Mass is neither created nor destroyed Mass is neither created nor destroyed when chemical and physical changes when chemical and physical changes occuroccur

Applies throughout universe and in all Applies throughout universe and in all branches of sciencebranches of science

LavoisierLavoisier

Created with determining Created with determining law of conservation of law of conservation of matter/massmatter/mass

First to recognize the role First to recognize the role of oxygen in burning and of oxygen in burning and rustingrusting

Guillotined during French Guillotined during French RevolutionRevolution

In-Class Assignment/HomeworkIn-Class Assignment/Homework

Learning Target InventoryLearning Target Inventory ColumnColumn

18.2 WKT18.2 WKT