Properties of Matter

Physical Properties

Ex.- color, shape, mass, volume,

density

Often identify objects based on

physical properties

Easy to observe

Pg. 60 answers: 1. c 2. d 3. d 4. a 5. c 6. a

Physical properties describe matter

Can be observed Can be measured

Stay constant for pure substances-

can be used in identification

Boiling & melting point constant if pressure remains the same

State- physical form in which a

substance exists

Density is a physical property

How much matter is contained in

a certain volumeDetermines whether

an object will sink or float

Calculated by dividing an object’s

mass by its volume

density=mass/volumeD=m/V

Which is heavier: a golf ball or

a ping-pong ball?

Have similar volume:14.1cm3

Golf ball has mass of 45.9g

Ping-pong ball has mass of 2.5g

D=m/VD=2.5g/14.1cm3

D=0.18g/cm3

D=m/VD=45.9g/14.1cm3

D=3.25g/cm3

Unit for density is normally g/cm3

cm3 is same as mLMay see g/mL as unit (especially liquids)

If 10.0cm3 of ice has a mass of 9.17g, what is the density of ice?

Mass= 9.17g Volume= 10.0cm3

D= m/VD= 9.17g/10.0cm3

D= 0.917g/cm3

Density Practice Problems Pg. 48

1. D = 7.31g/cm3

2. D = 3.26g/cm3

3. m = 76g

Physical properties help determine uses of materials

Are your socks clean?Property = odor

Does your shirt match your pants?

Property = color

Do all your books fit in your backpack?Property = volume

How are substances useful?

Copper can conduct electricity

well

Used in power lines, telephone lines,

and electric motors

Chemical Properties

Generally not as easy to observe as

physical properties

Related to the specific elements that make up substances

Describes how a substance changes into a new substance

Either by combining with other elements

or

By breaking apart into

new substances

Examples of chemical properties:-reactivity

-flammability

Substance always has its chemical properties

Comparing Chemical & Physical Properties

Physical properties:Can be observed without

changing the identity of the substance

Chemical properties:Can be observed only in situations in which the

identity of the substance changes

Many substances have similar physical propertiesbut completely different chemical properties

Baking soda and powered sugar

both white powders

Baking soda reacts with vinegar

Powered sugar does not

Characteristic properties help to identify and classify substances

Properties most useful in

identifying a substance

reactivity with acids

solubility

densityInclude both types-

physical and chemical

Always the same, no matter the sample size of the substance