Classification of Matter

MatterMatter

Matter: Anything that has mass and volume (takes up space)

3 phases of matter

The Nature of MatterThe Nature of MatterThe Nature of MatterThe Nature of Matter

Chemists are interested in the nature of matter and Chemists are interested in the nature of matter and how this is related to its atoms and molecules.how this is related to its atoms and molecules.

GoldGold MercuryMercury

Chemistry & MatterChemistry & Matter

• We can explore the We can explore the MACROSCOPICMACROSCOPIC world — what we can see — world — what we can see —

• to understand the to understand the PARTICULATEPARTICULATE worlds worlds we cannot see.we cannot see.

• We write We write SYMBOLSSYMBOLS to describe these to describe these worlds.worlds.

A Chemist’s View of A Chemist’s View of WaterWater

H2O (gas, liquid, solid)

MacroscopicMacroscopicMacroscopicMacroscopic

SymbolicSymbolicSymbolicSymbolicParticulateParticulateParticulateParticulate

A Chemist’s ViewA Chemist’s View

2 H2(g) + O2 (g) --> 2 H2O(g)

MacroscopicMacroscopicMacroscopicMacroscopic

SymbolicSymbolicSymbolicSymbolicParticulateParticulateParticulateParticulate

Kinetic Nature of MatterKinetic Nature of MatterKinetic Nature of MatterKinetic Nature of MatterMatter consists of atoms and Matter consists of atoms and

molecules in motion.molecules in motion.

STATES OF MATTERSTATES OF MATTERSTATES OF MATTERSTATES OF MATTER

• SolidsSolids — have rigid shape, fixed volume. — have rigid shape, fixed volume. External shape can reflect the atomic and External shape can reflect the atomic and molecular arrangement.molecular arrangement.

• LiquidsLiquids — have no fixed shape and may — have no fixed shape and may not fill a container completely. not fill a container completely.

• GasesGases — expand to fill their container— expand to fill their container. .

OTHER STATES OF MATTEROTHER STATES OF MATTEROTHER STATES OF MATTEROTHER STATES OF MATTER

• PLASMAPLASMA — an electrically charged gas; — an electrically charged gas; Example: the sun or any other starExample: the sun or any other star

• BOSE-EINSTEIN CONDENSATEBOSE-EINSTEIN CONDENSATE — — a condensate that forms near absolute zero a condensate that forms near absolute zero that has superconductive properties; that has superconductive properties; Example: supercooled Rb gasExample: supercooled Rb gas

Physical Physical PropertiesProperties– Characteristic of a substance that can be

observed (using your senses) without changing the substance into something else.

Physical properties are used to identify, describe and classify matter.

Hardness Texture Color

Odor Taste Temperature

More EXAMPLES - Physical

• size, shape, freezing point, boiling point, melting point, magnetism, viscosity, density, luster and many more.– Viscosity - The resistance of a liquid to

flowing.– Examples:– Low viscosity-water, rubbing alcohol– High viscosity-honey

Physical ChangesPhysical Changes– can be observed

without changing the identity of the substance

Some Some physical changes physical changes would would bebe

• boiling of a liquidboiling of a liquid• melting of a solidmelting of a solid• dissolving a solid in a liquid dissolving a solid in a liquid

to give a homogeneous to give a homogeneous mixture — a SOLUTION.mixture — a SOLUTION.

Physical Changes can bePhysical Changes can be

• Reversible include melting, freezing, boiling, condensing, and evaporating.

• Irreversible include breaking, splitting, grinding, crushing, and cutting.

Intensive/Extensive Properties

• extensive property - a property that depends on the amount of matter in a sample. Mass and volume are examples of extensive properties.

• intensive property - a property that depends on the type of matter in a sample, not the amount of matter.

• Every sample of a pure substance has identical intensive properties because every sample has the same composition. Hardness, color, conductivity, density and malleability are examples of intensive properties.

Chemical Properties

• Chemical properties are characteristics involved when a substance interacts with another substance to change its chemical make-up.

Flammability Rusting Creating gas bubbles

Creating a new chemical

product

Reactivity with water

pH

Chemical ChangeChemical Change

• Chemical change or Chemical change or chemical chemical reactionreaction — transformation of — transformation of one or more atoms or one or more atoms or molecules into one or more molecules into one or more different moleculesdifferent molecules..

•Burning hydrogen (HBurning hydrogen (H22) in ) in oxygen (Ooxygen (O22) gives H) gives H22O.O.

Possible Signs of a Chemical Possible Signs of a Chemical ChangeChange

• Heat- exothermic Heat- exothermic if given off, if given off, endothermic if endothermic if taken intaken in

• LightLight

• Gas Produced Gas Produced (not from boiling!)(not from boiling!)

• Precipitate – a Precipitate – a solid formed by solid formed by mixing two mixing two liquids togetherliquids together

• Color Change Color Change (sometimes)(sometimes)

A. Physical vs B. Chemical

• Examples:

– melting point

– flammability

– density

– magnetic

– tarnishes in air

physical

chemical

physical

physical

chemical

A. Physical vs B. Chemical

• Examples:

– rusting iron

– dissolving in water

– burning a log

– melting ice

– grinding spices

chemical

physical

chemical

physical

physical

Classification of Matter

• Now that we have defined chemical and physical properties of matter, we can use that to help us classify it.

• One way chemists classify matter is based on its purity.

Matter

Mixture Pure Substance

ElementCompoundHeterogeneous Mixture

Homogeneous Mixture

Can be separated physically

Cannot be separated physically

Can see the parts

Cannot see the parts

Can be separated chemically

Cannot be separated

Most impure Most pure

suspension colloid

Classification of Matter

• Pure Substance – Matter that has only 1 set of chemical and physical properties.

Example: Pure water always has the exact same chemical and physical properties under the same conditions.

If water ever tastes different then it isn’t pure water; it fits into our next category.

Classification of Matter

• Mixture – Two or more pure substances mixed together. Each substance in the mixture retains its own set of chemical and physical properties.

Example: Copper and Zinc can be mixed together to produce brass.

Even though it may look different, it is still copper and zinc. Each metal retains its own properties like melting point.

Classification of Matter

• Mixture – Two or more pure substances mixed together. Each substance in the mixture retains its own set of chemical and physical properties.

Unlike pure substances, mixtures can always be separated by physical means.

How could we separate the copper and zinc back out?

Mixtures

• Mixture – Two or more pure substances mixed together. Each substance in the mixture retains its own set of chemical and physical properties.

If a sample of sand contains iron and salt, how could you separate them from the other minerals?

Mixtures

• Some mixtures are more pure than others.• Heterogeneous mixture – Uneven distribution

of substances. (Very impure)- You can see the different parts.

Examples: SandGraniteWood

Mixtures

• Some mixtures are more pure than others.• Heterogeneous mixture – Uneven distribution

of substances. (Very impure)- You can see the different parts.

Examples: MilkBlood

Mixtures

• Homogeneous Mixture – Components are evenly mixed. (More pure than heterogeneous)

Salt water contains salt and water, but are mixed all the way to the atomic level

- Cannot see the parts.

, but it can still be separated by physical means. Seawater distillation plant

Pure Substances

• Pure substances can also be divided into 2 categories: compounds and elements.

Pure Substances

• Compound – Two or more elements chemically bonded together.

Examples:Carbon Dioxide (CO2)Water (H2O)Salt (NaCl)Sucrose (C12H22O11)

Pure Substances

• Compounds have only 1 set of properties. They cannot be separated by any physical process.- Can only be separated by a chemical reaction.

Water can be separated into Hydrogen and Oxygen by a process called Electrolysis.

Pure Substances

• Elements – Substances made up of only one type of atom. - Cannot be separated by any physical OR chemical process.

Examples:CarbonHeliumGold

Matter

Mixture Pure Substance

ElementCompoundHeterogeneous Mixture

Homogeneous Mixture

Can be separated physically

Cannot be separated physically

Can see the parts

Cannot see the parts

Can be separated chemically

Cannot be separated

Most impure Most pure

Classify the following slide using these five classifications:

- Non-matter- Heterogeneous Mixture- Homogeneous Mixture

- Compound- Element

HeliumHe Bronze

Cu + Sn

Electricity

SteelFe + C

WaterH2O

Cookie

AirN2 + O2 + Ar + CO2

Carbon DioxideCO2

Italian Dressing

IronFe

Salt WaterH2O + NaCl

DiamondC

Heat

Light

MercuryHg