Chapter Chapter 1515

Classification of Classification of MatterMatter

Sec. 1 Composition Sec. 1 Composition of Matterof MatterAll materials are either made of pure All materials are either made of pure

substances or mixtures.substances or mixtures.SubstanceSubstance—an element or compound.—an element or compound.ElementElement—a substance with atoms that are all —a substance with atoms that are all alikealike Ex. Carbon (C) & Magnesium (Mg)Ex. Carbon (C) & Magnesium (Mg) You can find them on the periodic table!!You can find them on the periodic table!!

CompoundCompound—a substance that contains 2 or —a substance that contains 2 or more elements combined chemically.more elements combined chemically. Ex. Table salt (NaCl) & Hydrogen peroxide (HEx. Table salt (NaCl) & Hydrogen peroxide (H22OO22))

MixturesMixturesMixtureMixture—a material made of 2 or more —a material made of 2 or more substances that can be separated physically.substances that can be separated physically.There are 2 types of mixtures: heterogeneous There are 2 types of mixtures: heterogeneous and homogeneous.and homogeneous.Heterogeneous MixtureHeterogeneous Mixture—different materials —different materials can be distinguished easily.can be distinguished easily. Ex. Pizza, salad, chocolate chip cookies (mmm)Ex. Pizza, salad, chocolate chip cookies (mmm)

Homogeneous MixtureHomogeneous Mixture—substances are —substances are blended evenly throughout.blended evenly throughout. Ex. Pop, vinegarEx. Pop, vinegar A homogeneous mixture is also called a A homogeneous mixture is also called a solutionsolution..

Colloids & Colloids & SuspensionsSuspensionsColloidColloid—a type of mixture that never settles.—a type of mixture that never settles.

Ex. Paint & fogEx. Paint & fog

A colloid is A colloid is notnot the same as a solution the same as a solution Colloids often appear foggyColloids often appear foggy If you shine a light on a colloid, you can see the If you shine a light on a colloid, you can see the

light reflected from the colloid.light reflected from the colloid.

SuspensionSuspension—a heterogeneous mixture —a heterogeneous mixture containing a liquid in which visible particles containing a liquid in which visible particles settle.settle. Ex. Mud in a pond & river deltas Ex. Mud in a pond & river deltas

How to Classify MatterHow to Classify Matter

ElementElementSubstance Substance

CompoundCompoundMatterMatter

HeterogeneousHeterogeneousMixtureMixture

Homogeneous or Homogeneous or solutionsolution

Sec. 2: Properties of MatterSec. 2: Properties of MatterPhysical PropertiesPhysical Properties—any characteristic of —any characteristic of a material that you observe without a material that you observe without changing its substances.changing its substances. Ex. Color, shape, size, melting & boiling pointEx. Color, shape, size, melting & boiling pointSome physical properties describe Some physical properties describe behavior.behavior. Magnetism, conduct electricity, viscosity, Magnetism, conduct electricity, viscosity,

dissolving.dissolving.You can separate mixtures using physical You can separate mixtures using physical properties.properties. Size, color, magnetism, etc.Size, color, magnetism, etc.

Physical Changes/Chemical PropertiesPhysical Changes/Chemical Properties

Physical changePhysical change—a change in size, shape, —a change in size, shape, or state of matter (solid, liquid, gas)or state of matter (solid, liquid, gas) The identity of the substance doesn’t change.The identity of the substance doesn’t change. Ex. Freezing, ripping, folding, dissolving.Ex. Freezing, ripping, folding, dissolving.

Chemical PropertyChemical Property—a characteristic of a —a characteristic of a substance that tells if it can undergo a certain substance that tells if it can undergo a certain chemical change.chemical change. Ex. Flammability, reaction to lightEx. Flammability, reaction to light

Chemical Properties & ChangesChemical Properties & Changes

Chemical ChangeChemical Change—a change of 1 —a change of 1 substance to another.substance to another. Ex. Rotten eggs, rust, burning.Ex. Rotten eggs, rust, burning.

Detecting Chemical Changes:Detecting Chemical Changes: Odor, heat, light, sound, release gas (bubbles), Odor, heat, light, sound, release gas (bubbles),

Separating Substances:Separating Substances: Ex. Cleaning tarnished silver, purifying metals.Ex. Cleaning tarnished silver, purifying metals. A chemical change will change the substances, A chemical change will change the substances,

so it cannot be used to separate a mixture.so it cannot be used to separate a mixture.

WeatheringWeatheringWeathering is how Earth’s surface changes.Weathering is how Earth’s surface changes.Weathering is a result of both physical & Weathering is a result of both physical & chemical changes.chemical changes.PhysicalPhysical:: ice wedging (ice in cracks expands ice wedging (ice in cracks expands & breaks the rocks), & streams cut through & breaks the rocks), & streams cut through softer rock.softer rock.ChemicalChemical: limestone dissolves in acidic : limestone dissolves in acidic ground water (canyons & caves are formed ground water (canyons & caves are formed this way)this way)

Conservation of MassConservation of MassLaw of Conservation of MassLaw of Conservation of Mass—the mass —the mass of all substances before a chemical or of all substances before a chemical or physical change equals the mass of all physical change equals the mass of all substances after the change.substances after the change.In other wordsIn other words: mass is neither created or : mass is neither created or destroyed during any chemical or physical destroyed during any chemical or physical change.change.