Properties of Matter

OBJECTIVES:

– Identify properties of matter as extensive or

intensive.

– Define physical property, and list several

common physical properties of substances.

– Differentiate among three states of matter.

– Describe a physical change.

MATTER

Matter is anything that:

a) has mass, and

b) takes up space

MASS a measure of the amount of “stuff”

(or material) the object contains (don’t

confuse this with weight, a measure of

gravity)

VOLUME

a measure of the space occupied by

the object

Which do you think would have the

greater volume and mass? Why?

1 kg of feathers

1 kg of rock

Density is defined as mass per unit volume. It is a measure of how tightly packed and how heavy the

molecules are in an object. Density is the amount of matter within a certain volume.

Proof that water and ice have

different densities

Ice floats in water

4OC water is at its

densest state

Water molecules

behave anomalously as

it freezes

8

To find the density

1. Find the mass of the

object

2. Find the volume of

the object

3. Divide

Density = Mass

Volume

Units for density g/cm3 or g/ml

Formula: M = mass V= volume D = density

D = M / V

M = D x V

V = M / D

1) Find the mass of the object

2) Find the volume of the object

3) Divide : Density = Mass - Volume

To find density:

Ex. If the mass of an object is 35 grams and it takes up 7 cm3 of space, calculate the density.

1) Find the mass of the object

2) Find the volume of the object

3) Divide : Density = Mass - Volume

To find density:

Set up your density problems like this:

Given: Mass = 35 grams Unknown: Density (g/ cm3) Volume = 7 cm3

Formula: D = M / V Solution: D = 35g/7 cm3

D = 5 g/cm3

Ex. If the mass of an object is 35 grams and it takes up 7 cm3 of space, calculate the density.

Properties are… Words that describe matter (adjectives)

Physical Properties- a property that can be observed and measured without changing the material’s composition.

Examples- color, hardness, m.p., b.p.

Chemical Properties- a property that can only be observed by changing the composition of the material.

Examples- ability to burn, acidity, reaction with oxygen, reaction with water, reaction with acid and bases, reaction with metal, decompose, ferment, etc.

Physical Properties Properties used to describe matter without changing

its identity. It can be classified as:

1) Extensive – depends on the amount of

matter in the sample

- Mass, weight , thickness, area, height, volume, calories, shape, length

2) Intensive – depends on the type of

matter, not the amount present

-color, odor, taste, elasticity, porosity, hardness, density, freezing and boiling point, specific gravity

Chemical Properties

chemical properties of matter is matter

based on its ability to participate in

chemical reactions and form new

substances. Some chemical properties

are:

1. Reaction with oxygen (combustion)

2. pH (reaction with Acids and Base)

3. Corrosion

4. Decomposition into simpler substance

COLOR

A visual attribute of things that results from the

light they emit, transmit or reflect

ODOR

smell or the sensation that results when

receptors in the nose are stimulated by particular

chemicals in gaseous form

LUSTER

The visual property of something that shines with

reflected light

OPACITY

The phenomenon of not permitting the passage of

electromagnetic radiation

MALLEABILITY The property of being

physically malleable; the

property of something that can

be worked, hammered or

shaped without breaking

DUCTILITY The malleability of

something that can be drawn into

threads, wires or hammered into

thin sheets

CONDUCTIVITY

A material's capacity to conduct electricity, sound, heat

HARDNESS

The property of being rigid and resistant

to pressure; not easily scratched; measured on

Mohs scale

MELTING POINT

The temperature below

which a liquid turns into a solid

BOILING POINT

The temperature

at which a liquid boils at

sea level

DENSITY

amount of

mass per volume MASS

amount of matter

WEIGHT

The vertical force

exerted by a mass as a

result of gravity

VOLUME

The amount of 3-dimensional space occupied by an object

LENGTH

longest side of an object. A distance between 2 points

VISCOSITY

resistance of liquid to flow

SOLUBILITY

(solution) the quantity of a particular substance that can

dissolve in a particular solvent (yielding a saturated solution)

VOLATILITY

The property of changing readily from a solid or liquid to

a vapour

States of matter

Solid- matter that can not flow (definite

shape) and has definite volume.

A. Incompressible, rigid and compact

B. Do not flow

C. Melt

Liquid- definite volume but takes the

shape of its container (flows).

A. Ability to flow and viscosity

B. Diffusion

C. Definite volume

D. Surface tension

E. Capillary action

F. Vaporization or evaporation

A phenomenon associated with surface tension and

resulting in the elevation or depression of liquids in capillaries

CAPILLARY ACTION

SURFACE TENSION

is a contractive tendency

of the surface of

a liquid that allows it to

resist an external force

the process in which there is movement of a

substance from an area of high concentration of

that substance to an area of lower concentration

Diffusion

Gas- a substance without definite volume

or shape and can flow.

A. It has no definite shape and volume

B. It diffuses easily. It flows

C. It can be compressed.

D. It exerts pressure.

States of Matter

Solid

Liquid

Gas

Definite

Volume?

YES

YES

NO

Definite Shape?

YES

NO

NO

Result of a

Temperature

Increase?

Small

Expans.

Small

Expans.

Large

Expans.

Will it Compress?

NO

NO

YES

4th state: Plasma - formed at

high temperatures; ionized phase

of matter as found in the sun

Three Main Phases

Solid Liquid Gas

Melt Evaporate

Condense Freeze

Copper Phases - Solid

Copper Phases - Liquid

Copper Phases – Vapor (gas)

Physical vs. Chemical Change Physical change will change the visible

appearance, without changing the composition of

the material.

– Boil, melt, cut, bend, split, crack

– Is boiled water still water?

Can be reversible, or irreversible

Chemical change - a change where a new

form of matter is formed.

– Rust, burn, decompose, ferment

Examples of Physical Change water evaporating or water changing to

steam

clothes drying in a dryer

chopping wood - wood ground to sawdust

erosion

rock breaking

mixing Kool-Aid

Examples of Chemical Changes

fruit rotting, food spoiling

rust

decay of plants

burning wood

silver tarnishing

car burning gas

baking bread

Chemical Changes The ability of a substance to undergo

a specific chemical change is called a

chemical property.

• iron plus oxygen forms rust, so the

ability to rust is a chemical property

of iron

During a chemical change (also called

chemical reaction), the composition of

matter always changes.

Chemical Reactions are… When one or more substances are

changed into new substances.

Reactants- the stuff you start with

Products- what you make

The products will have NEW

PROPERTIES different from the

reactants you started with

Arrow points from the reactants to the

new products

Chemical Change Evidence

1. Precipitate forms (solid)

2. Gas evolves (bubbles)

3. Color change

4. Energy change » Exothermic = releases energy

» Endothermic = absorbs energy

5. Odor produced (sometimes)

6. Irreversibility - not easily reversed

But, there are examples of these that are not

chemical – boiling water bubbles, etc.

Chemical changes Physical changes

Rusting of nails

Baking cake

Fermentation of rice

washing

Tarnishing of a silver

spoon

Dissolving antacid in

water

Setting of a jelly

Melting butter

Boiling water

Sawing a board in half

Breaking a glass

Conservation of Mass During any chemical reaction, the

mass of the products is always equal

to the mass of the reactants.

All the mass can be accounted for:

–Burning of wood results in products

that appear to have less mass as

ashes; where is the rest?

Law of conservation of mass

- Page 55

reactants = product

43.43 g Original mass = 43.43 g Final mass

1. Is this a physical or chemical change?

dirt added to a pond of water

Physical Change

2. Is this a physical or chemical change?

making whip cream

Physical Change

3. Is this a physical or chemical change?

baking soda fizzes with vinegar

Chemical Change

4. Is this a physical or chemical change?

sharpening a pencil

Physical Change

5. Is this a physical or chemical change?

a stick broken into small pieces

Physical Change

6. Is this a physical or chemical change?

sugar turns brown, then black with heat

Chemical Change

7. Is this a physical or chemical change?

using hot water to expand a metal cup

Physical Change

8. Is this a physical or chemical change?

freezing water

Physical Change

9. Is this a physical or chemical change?

cornstarch turns black with iodine

Chemical Change

10. Is this a physical or chemical change?

toasting a marshmallow

Chemical Change