Matter: Properties & ChangeMatter: Properties & ChangeChapter 3

MatterMatter

Matter – anything that has mass and takes up space

Everything around us

Chemistry – the study of matter and the changes it undergoes

Four States of MatterFour States of Matter

Solidsparticles vibrate but can’t move

aroundfixed shape fixed volumeincompressible

Four States of MatterFour States of Matter

Liquidsparticles can move

around but are still close together

variable shapefixed volumeVirtually incompressible

Four States of MatterFour States of Matter

Gasesparticles can separate and

move throughout containervariable shapevariable volumeEasily compressedVapor = gaseous state of a

substance that is a liquid or solid at room temperature

Four States of MatterFour States of Matter

Plasmaparticles collide with enough energy

to break into charged particles (+/-)gas-like, variable

shape & volumestars, fluorescent

light bulbs, TV tubes

Physical PropertiesPhysical Properties

Physical Propertycan be observed without changing the

identity of the substance

Physical PropertiesPhysical Properties

Physical properties can be described as one of 2 types:

Extensive Propertydepends on the amount of matter

present (example: length)

Intensive Propertydepends on the identity of substance, not

the amount (example: scent)

Extensive vs. IntensiveExtensive vs. Intensive

Examples:boiling point

volume

mass

density

conductivity

Density – a physical propertyDensity – a physical property

Derived units = Combination of base units

Volume (m3 or cm3 or mL) length length length Or measured using a

graduated cylinder

D = MV

1 cm3 = 1 mL1 dm3 = 1 L

Density (kg/m3 or g/cm3 or g/mL)mass per volume

DensityDensity An object has a volume of 825 cm3 and a

density of 13.6 g/cm3. Find its mass.

GIVEN:

V =

D =

M = ?

WORK:

V

MD

DensityDensity A liquid has a density of 0.87 g/mL. What

volume is occupied by 25 g of the liquid?

GIVEN:

D =

V =

M =

WORK:

V

MD

DensityDensityM

ass

(g)

Volume (cm3)

Δx

Δyslope D

V

M

= g/cm3units of yunits of x

Units of the slope

ProportionsProportions

Direct Proportion

Inverse Proportion

xy

xy

1

y

x

y

x

Percent ErrorPercent Error

Indicates accuracy of a measurement

100literature

literaturealexperimenterror %

your value

accepted value

Percent ErrorPercent Error

A student determines the density of a substance to be 1.40 g/mL. Find the % error if the accepted value of the density is 1.36 g/mL.

100g/mL 1.36

g/mL 1.36g/mL 1.40error %

% error = 0.04/1.36 = 3 %

Chemical PropertiesChemical Properties

Chemical Propertydescribes the ability of a substance to

undergo changes in identity

Physical vs. Chemical PropertiesPhysical vs. Chemical Properties

Examples:melting point

flammable

density

magnetic

tarnishes in air

Physical ChangesPhysical Changes

Physical Changechanges the form of a substance without

changing its identity

properties remain the same

Examples: change in shape or size, dissolving, change in color by dying, all phase changes,

Phase Changes – PhysicalPhase Changes – Physical

Evaporation =

Condensation =

Melting =

Freezing =

Sublimation =

Chemical ChangesChemical Changes

Process that involves one or more substances changing into a new substanceCommonly referred to as a chemical

reactionNew substances have different

compositions and properties from original substances

Chemical ChangesChemical Changes

Signs of a Chemical Changechange in color or odor (not by dying)

formation of a gas (bubbling)

formation of a precipitate (solid)

change in light or heat

Physical vs. Chemical ChangesPhysical vs. Chemical Changes

Examples:rusting iron

dissolving in water

burning a log

melting ice

grinding spices

What Type of Change?What Type of Change?

Matter FlowchartMatter Flowchart

MATTER

Can it be physically separated?

yes no

Can it be chemically decomposed?

noyesIs the composition uniform?

noyes

Pure SubstancesPure Substances

Elementcomposed of identical atomsEX: copper wire, aluminum foil

Pure SubstancesPure Substances

Compoundcomposed of 2 or more

elements in a fixed ratio

properties differ from those of individual elements

EX: table salt (NaCl)

MixturesMixtures

Variable combination of 2 or more pure substances.

Heterogeneous Homogeneous

MixturesMixtures

Solutionhomogeneousvery small particlesparticles don’t settleEX: rubbing alcohol

MixturesMixtures

Heterogeneousmedium-sized to

large-sized particles

particles may or may not settle

EX: milk, fresh-squeezed

lemonade

MixturesMixtures

Examples:tea

muddy water

fog

saltwater

Italian salad dressing